Here are the steps to move a file from OneDrive to Microsoft Teams:
Step 1:
Sign in Microsoft Teams with your Office 365 account,
Step 2:
navigate to Files > Cloud Storage > OneDrive
Select a file. example: Book5.xls
Step 3:
Select Move > Browse Teams and Channels > choose the location and click Move.
Step 4:
Then you can check the file in Teams > Files.