SFDX App
ApigeeAuthProvider
Dev -- Deploy to Scratch Org
sfdx force:org:create -f config/project-scratch-def.json -a MyScratchOrg
sfdx force:source:push -u MyScratchOrg
Dev -- Deploy to Sandbox
sfdx force:source:convert -d temp/ --packagename ApigeeAuthProvider
sfdx force:mdapi:deploy -d temp/ -u "sandbox_username" -l RunSpecifiedTests -r ApigeeAuthProviderTest
FAQ
When configuring the AuthProvider, make sure that you set Name and URL Suffix to the same value! If you don't then you must override the Callback URL. See #1