Linking to SharePoint from Teams
Add a tab at the top of your Team site that links to a folder on SharePoint
Open Teams, navigate to your Team and the Channel where you want the link to appear
Click the + at the top
Click Document Library
Select your document library if it appears under Relevant Sites, otherwise select Use SharePoint Link and paste in the URL to your SharePoint site
Check Post to the channel about this tab to alert your teammates about the new tab
Click Next
Select the document folder that you want to link to. If you have more than one to link to, you can link to more by following these instructions again
I recommend naming your new tab SharePoint Files or something like that
Click Save