I replaced several similar thermostats with Maestro by Stelpro ones a few years ago. They work well enough. Not sure if they still make them.
You need a thermostat specifically for line voltage. The only one I’m aware of is Mysa, and they are $100+/each. There’s no cheap option unfortunately, especially if you’re like me and have 9 of them in the house.
No unfortunately MYSA won’t work, when i fill out the "check your compatibility " section it’s says it won’t work :/
I use the Maestro line by Stelpro of line thermostats. they don’t play with Alexa, Siri etc. but they have a phone app that does everything I need. As said, not cheap ~$100 each.
You can get a SPST relay with a 24 volt coil on Amazon for $15.00 A 24 volt transformer is less than $20. And you can then pick a thermostat of your choice. I use a Ecobee. I can give it commands via Alexa or Home Assustant
Same, but they do work well with IFTTT