Follow the below mentioned steps to install from Google Workspace Marketplace
Step 2 : You will get installation window. click on INSTALL
Step 3 : Map my sheet will ask your permission to installing. Click CONTINUE
Step 4 : Then it takes you to Authentication window. there you have to select your account .
Step 5 : click Allow That will completes your Authentication process.
Step 6 : Finally click on Done. That Completes your Installation process.
Now your Map My Sheet is ready to use.