Condition on Workflow Action status


I’m New to ERPNext,
I need to put some conditions on workflow action status,

I Created Workflow like Approved ->Start → Started
Approved & Started are statuses of the workflow,
And “Start” is the action of the workflow, once this action is selected by the user then one dialog should be prompted and it should ask OTP number,

In a prompt dialog box, there will two buttons 1. Verify and 2.Cancel

kindly guide me on what I need to follow to add these features to ERP next Doctype.

Thank you in advance and waiting for a valuable response.