I discovered that I had set up my Stripe payment account (to service my paid subscribers here at Substack) using a different email address than the email address which I used to set up my Substack account. So, I no longer have a problem with anyone wanting to sign up for a paid subscription and I am unfreezing the autopayment feature on my account.
For the sake of redundancy, here are three additional alternatives by which you may donate to me via Venmo or PayPal or Patreon …
https://www.venmo.com/u/vinyasi
https://www.patreon.com/c/Vinyasi