Can you make "<<_ATTACHMENTFILE_URL>> Built in Variable to output the Google Drive attachment link?

Does not looks good.
For the purpose of debug, I suggest we start with the default file path first. Could you remove the you custom file path out of your workflow and make it blank? Then use the expression like this.

CONCATENATE(“https://www.appsheet.com/template/getappfileurl?appName=",“AstrivisCRM-1210465”,"&tableName=",“crm_tasks”,"&fileName=",“Attachments%2F”,"WorkFile_for_Task_",encodeurl([task id]),"_",encodeurl([task title]),".pdf")

Troublesome, but the step by step approach is always the shortest way to reach the goal.

This is expression where the pdf file will be saved to default folder with name of Attachments. Test this out first if this returns right full path. With positive test, then change the folder path part to meet your own and custom relative path. This is proper debug process.

Maybe the custom attachment name as well?

yes if you never mind.

For instance, name the attachment file as “test”.
Then expression will be simply like

CONCATENATE(“https://www.appsheet.com/template/getappfileurl?appName=",“AstrivisCRM-1210465”,"&tableName=",“crm_tasks”,"&fileName=",“Attachments%2F”,"test.pdf")

now looks super simple!

But doesn’t that output the same thing as _ATTACHMENTFILE_URL variable? I just realized that now

Yes, but we are going to reach the same file, dont worry.
There are few different ways to do the same.

I’m sorry if I’m completely not comprehending this, but how will that help me output the google drive file link? Because that one is always something like:

`

https://drive.google.com/file/d/1abQhSON3uGmEJb8ZGo_xx/view?usp=sharing

`

That is URL sharable link which Google provide. To get that sort of URL, we need to get file IDs. Instead of those google native i would say URL, Appsheet is providing a way to reach to your file with expression we are talking here.

Again forget about Google sharable url, as well as url which template variable returns.
We are talking about the same stuffs, but from different angles.

To capture the google file IDs, it is tricky. Appsheet does not have native support to that. But they are giving a way to construct URL to reach to the file on any cloud service you are hosting. We are looking and accessing to the file you save through appsheet app, through Appsheet hosting server, so URL looks different, thats about it.

I understand that, but the purpose of my post was to find out if I can somehow compute the google drive link, because I have no problem with including the https://www.appsheet.com/template/getappfileurl?appName= types of URL’s in my email templates

Oh, sorry I miss-read your post and query.
To construct ULR alike google sharable link, then there is no native feature to do it for now. Only Google Apps Script could do, to get file Ids, but I understand it wont make sense with you.

But providing URL to your apps user with URL starting with appsheet.com is to give the same experience to your end users.

Actually, I do have hyperlinks to the saved attachment files on all of my apps as well.