@danoakes & @rikpare Apologies for the late response, but this is most likely happening if the image URLs don’t point directly to the file (such as a file with URL arguments or one that loads a webpage instead of the file directly-- Dropbox and Google Drive links are examples), if they don’t have a file extension in the URL, or if they are password protected. You can test the URL by opening a private browser window and pasting the URL into the address bar. If the file doesn’t load, it’s probably set to be private. If it loads in a frame (such as with Dropbox and Google Drive), then the URL won’t work. If it’s a matter of the link missing a file extension, if you add the correct file extension to the downloaded file, it will import, as the file is not corrupt, but it’s that After Effects depends upon the file extension to import a file. Any file without a file extension will not import into After Effects.
You have the ability to write a shell script on the “Pre-Data” event. See event [ 2a ] in our table of events that Templater broadcasts. In that script, you can run any commands needed to retrieve an API access token. Does this help?
For remote URL data sources, Templater supports Basic Authentication at the moment. How are you expecting to use the API access token once you retrieve it? Are you wanting to send it with request Templater makes? If so, I’m not sure that’s possible out of the box even with scripting. However, you should be able to get the API token via a shell script by registering it to the “Pre-Data” event.
Also, don’t forget that you may need to enable the “Tab delimited file exported from Excel or Numbers” checkbox within the Templater Preferences dialog to work with TSV data exported or saved from Microsoft Excel.