Google slides HTTP requests API's

Question

I am a bubble.io developer but ran into a problem I haven't had previously, trying to push data (just creating a new slide) from bubble.io to google slides using the following API:

https://slides.googleapis.com/v1/presentations/[presentationId]:batchUpdate

Where presentationId is the name of the file which is added as an extra parameter.

Snapshot of bubble API

I used the following JSON: JSON snapshot

When I "Initialize the call" I get the following error:

Initilization error

Can anyone please assist as my OAUTH and Scopes are all correct.

Thank you very much.