Is there a limit to the number of triggered emails you can send? Such as a per month, per day, limit? As far as I know there isn’t a limit, and it’s free to send them, is this true?
That question would be better directed straight to Wix Support as it is regarding Wix Ascend and not code for which this forum is designed for.
https://support.wix.com/en/article/contacting-wix-support
https://support.wix.com/en/article/ascend-plans
If you are just looking for free things then this is your limit per month.
https://support.wix.com/en/article/using-wix-email-marketing-for-free
If however, you are talking about code like for this tutorial here with the use of SendGrid.
https://support.wix.com/en/article/corvid-tutorial-sending-an-email-on-form-submission
Then note that SendGrid is a third party and has it’s own pricing plans.
https://sendgrid.com/pricing/