Starting November 9th, 2020, Microsoft announced that end users will no longer be able to grant consent to newly registered multi-tenant apps without verified publishers.
To use the Strategy SharePoint Files connector, you need to register an app to support OAuth authentication to Microsoft Azure.
You are required to complete the following 4 steps for a successful configuration:

https://your-host-name/CommunityConnectors/redirect

Files.Read.All profile Sites.Read.All User.Read



config.jsonfile under
webapps/CommunityConnectors/sharepointfiles/config.json.
"oauth.authorize_uri": {
"value": "https://login.microsoftonline.com/common/oauth2/v2.0/authorize",
"editable": false
},
"oauth.token_uri": {
"value": "https://login.microsoftonline.com/common/oauth2/v2.0/token",
"editable": false
}
Please refer to KB484387.