This guide walks you through installing an extention in SharePoint Online.
Navigate to your SharePoint admin center - either located in the “Classic SharePoint admin center”
https://[yourtenant]-admin.sharepoint.com/_layouts/15/online/tenantadminapps.aspx
Or in “Classic features”
If you haven’t configured an App Catalog yet, check out this video to see how https://www.youtube.com/watch?v=xEc8X7VVtc8
Click on (1)
Click Upload
Upload the [app].SPPKG file
If the option dialog do not appear, then select “Deploy” in the Ribbon
When the file has been uploaded, SharePoint will give you the option to “Make this solution available to all sites in the organization” or not.
Disregard the following statement as the Toolbar is an extension. not a web part.
If you clear this setting, users won’t be able to add the web part to pages. The web part will continue to work if it was already added to pages.
Instead, read more about Tenant-scoped solution deployment for SharePoint Framework solutions
If you did select “Make this solution available to all sites in the organization” the extention will be available to all site collections in your tenant and the value in column “Tenant Deployed” will be Yes
If you have just created the app catalog, you might see that the deployment failed. Check this to learn what to do https://support.shortpoint.com/support/solutions/articles/1000269130-known-issue-shortpoint-spfx-app-deployment-error-deployment-failed-correlation-id-guid-
At the root site of your SharePoint Online site, create a document library called "jumpto365"
If you did not select “Make this solution available to all sites in the organization” when you deployed the extention, you need to install the “App” individually on each site collection
Click the Gear icon then “Add an app”
Select “From Your Organisation”
Wait a few seconds
Refresh the page and verify the “GlobalToolbar” is no longer greyed out
Navigate to site content and local the “GlobalToolbar”
Click on the menu
Select “Remove”
Accept that Microsoft might not have integrated this function in Modern, so click “Return to classic SharePoint”. Note that this doesn’t convert the current site to Classic.
Select “Remove”
And finally OK