A fair question, does anyone know why not?

"I'm in the process of migrating from Twitter to Mastodon and was surprised to discover that there are no *-to-Mastodon apps at IFTTT (for example, no Instagram-to-Mastodon app to replace my current Instagram-to-Twitter app). I would have thought since Mastodon was open source, there'd be many of them. Even if I go to "Create" and scroll through the available services, Mastodon is not offered as a service option."

https://www.reddit.com/r/ifttt/comments/z1hxmr/why_no_mastodon_support_at_ifttt/