Do you know about the “16 personalities”?

“Do you know about the MBTI test?

I nodded in conviction.(acknowledgement / agreement)

"conviction" is a _very_ strong phrase. It's the type of thing you might say about someone resolved to enter a life threatening situation like a soldier entering a war or a rescuer entering a burning building. At other times it can have a negative connotation, like the conviction of a religious zealot. It doesn't really fit for nodding along to a coworker.

Agreement would work if you agreed that your coworker was a natural entertainer, or acknowledgement would work if you're just indicating that you've heard about the MBTI test.

In my company, I have been assigned to a task team whose purpose is promoting informal communication inside the workplace and fostering psychological safety.

That colleague actively kept writing something short and funny things in the chatbox, and helped us creatinge an exciting, neat atmosphere during the meeting.

"kept writing something short and funny" - he wrote one thing over a long time
"kept writing short and funny things" - he wrote many times

The utterance in the first line was her reply to me for my thank-you message after that meeting.

The result was somewhat convincing for me, but I also thought that it was not that stableconsistent of a test and that I could have different results each time I try it.

I reported to her, “I tried MBTI and found that I’m an INFP type(that one(the kind who is playings with flowers).” Then she replied, “I knew that you’ were that sort of person (that playings with flowers)!”

“Do you know what an MBTI test is?

I am “'an entertainer”' by nature, you know.” said my colleague.

Quotation marks within quotation marks are single '

I nodded in convictionagreement.

"Nodded in agreement" is the correct term

InAt my company, I have been assigned to a task team whose purpose is promoting informal communication inside the workplace and fostering psychological safety.

As a part of that activity, today we held a kickoff meeting for an event online today.

That colleague actively kept writing something short and funny messages in the chatbox, and helped us in creating an exciting, neat atmosphere during the meeting.

"Kept writing" implies "actively" already
"Something" is just one thing

The utterance in the first line was her reply to me my thank-you message after that meeting.

Then I tried MBTItook the MBTI test.

The result was somewhat convincing for me, but I also thought that it was not that stablan accurate test, and I could have different results each time I try it.

I reported to her, “I tried MBTIthe MBTI test and found that I’m an INFP type(that one who is playing with flowers).” Then she replied, “I knew that you’re that sort of person (playing with flowers)!”

“Do you know what an MBTI test is?

I am “an entertainer” by nature, you know.” said my colleague.

I nodded in convictionagreement.

I'm not sure what you're trying to say here

In my company, I have been assigned to a task team whose purpose is promoting informal communication inside the workplace and fostering psychological safety.

At my company, I’ve been assigned to a task team whose purpose is promoting informal communication inside the workplace and fostering psychological safety.

As a part of that activityinitiative, today we held a kickoff meeting for an event online.

ThatOne colleague actively kept writing something short and funny in the chatbox, andwhich helped us creatinge an exciting, neat and friendly atmosphere during the meeting.

The utterasentence in the first line was her reply to me my thank-you message after thate meeting.

The result wasfelt somewhat convincing forto me, but I also thought that it was not thatn’t a very stable test and I could havethat I might get different results each time I tryook it.

I reported to her, “I tried MBTI and found that I’m INFP type (that one who is playing with flowers).” Then she replied, “I knew that you’re that sort of person (playing with flowers)!”

“Do you know about the MBTI test?

"I am “an 'entertainer”' by nature, you know.,” said my colleague.

When we use quotes within another quote, we use a single quote instead of double.

I nodded inwith conviction.

You might have meant nodded "in agreement" here.

That colleague kept actively kept writing something short and funny messages in the chatbox, andwhich helped us creatinge a neat, exciting, neat atmosphere during the meeting.

Some of these corrections aren't completely necessary, but it sounds a lot more natural this way in my opinion.

The utterance in the first line was her reply to me my "thank- you" message after that meeting.

It is true that we use a hyphen to join 2 words that both modify the following noun, but I think here we would more likely just use quotes.

Then, I tried MBTI.

The result was somewhat convincing for me, but I also thought that it was not that stable of a test, and I couldmight have different results each time I tryied it.

I reported to her, “I tried MBTI and found that I’m INFP type( - that one who is playing with flowers).” Then she replied, “I knew that you’re that sort of person (- playing with flowers)!”

We wouldn't normally put something in parentheses that was actually said. If these words were not actually said, then we would not put them inside the quotes.