If you install Annotate PRO for Microsoft Word (instructions here) you should have access to AP within the version of Word that runs inside Microsoft Teams. However, the configuration set by your IT admin or other factors could cause AP to not show up within Teams. The good news is, it’s very easy to fix!
How to Install AP for Teams/Word
The steps for installing AP for Word inside Teams are the same as for installing it for the desktop version of Word. The only difference is that the menu layout is slightly different between the two versions in one step.
From step three of the Installation guide, instead of finding “Get Add-ins” from the Insert tab, you need to expand the additional options using the … at the far-right of the Home pane. This will expand with more options, the final one being “Add-ins”. Once you click on “Add-ins” you need to clikc the “+ More Add-ins” button which will open the Office Store and you can continue with the installation steps as normal.