I think Teams use the same format as the forum so go to your post and click on the down arrow to the right of it and click Edit Post. You have to put something so either put "Self Deleted" or just a "." and then submit. On the forum you only get an hour to edit it so I would assume it is likely to be the same on Teams.
If you are too late to Edit it and you absolutely want it removed then you can report your own post and tell the moderators that you want it deleted.
