I wasn’t able to find the API key from the docs you shared. Where can I get one from?
Your API key should be in your Cloudinary Dashboard.
I’m posting a curl command that works and then I’m going to see if I can get it to work using Thunkable blocks:
curl --location --request POST 'https://api.cloudinary.com/v1_1/[YOUR CLOUD NAME]/image/upload?upload_preset=rpcv1fz5' \
--header 'api_key: [YOUR API KEY]' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'file=data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=='
Granted, this is with an unsigned upload. I haven’t been able to get it to work with a signed (secure) upload.