I had been using the Todoist Pack (Todoist Pack, extend Coda with Todoist | Coda) but it stopped working for me - just gives errors. I tried contacting the developer a couple times, but got no response. But as I only use one action from that pack, I thought I might try writing my own - and it seems to be working just fine!
This is the first time I’ve tried writing anything like this, and I’m pretty pleased with the result. I know that Todoist deprecated their v1 API last month (I use Make/Integromat, so I found out about the change there), so this is written with their new v2 API. It’s nothing fancy, just a button to close a task. So if the other pack has stopped working for you, too, and you just need a “mark done” button, here you go: Coda Packs extend how your doc looks, works, & integrates - Coda