Hey Guys,
I've since realised that an OAuth 2 Token asset was added in a later version of Matrix, which luckily I have access to and can use.
The authentication now appears to be working - the token asset stores the token and my REST resource is pulling the JSON as expected.
I'm now running into an issue where my JSON Data Source asset is throwing a Matrix warning ('Events' is the name of the JSON Data Source asset):
MySource Warning Syntax error: Events (Id: #214222)
The JSON in the REST resource is valid (after checking 'Run Test'), so I'm not sure what the issue is here. The JSON Data Source asset is displaying nothing when I check the 'View JSON Data' page and it won't load any shadow assets in the asset map, with error "Error while requesting".
Any suggestions?