This is only for using ACH/ echeck recurring with Stripe recurring. eCheck/ACH one-off are not supported with Stripe. Refer to the following article for details
Note: We have been using Stripe for long time for credit card processing and other payment methods in some regions. However ACH/echeck is new to customers for stripe. Therefore, we recommend that you test thoroughly before deploying to production. We have had customers using ACH/echeck with authorise.net for many years.
Prerequisite of this include setting up stripe webhook completely. Refer to the stripe setup article.
When someone signs up using eCheck, a Recurring Payment is created with the status “Awaiting Verification”:

At that point, a workflow alert titled "Send Email New Direct Debit Verification Instructions (Managed)" is triggered and sends an email to the client. If you're not seeing this email go out, the workflow might be inactive in your org and may need to be activated.
Ref: Please look at the following article steps 2 and 3 - The workflows need to be turned on to receive that email.
The "Verify Account" button prompts the user to enter the two small deposit amounts sent to the customer's bank account. Until that step is completed, the recurring payment remains unverified and inactive.
Note: this button is only accessible to Salesforce users

To accommodate this process, we recommend updating the verification email template to clearly explain that:
- As part of the verification process, two small deposits will be made to their account.
- Once they receive those, they should call your team at XXX-XXX-XXXX.
- Your team will then verify the amounts and activate the recurring payment on their behalf.