Fix Play Console Key Mismatch

My Android release hits a road-block on Google Play Console because the SHA-1 key of the .aab I am uploading no longer matches the signature Google has on record. The problem is that I no longer have the original keystore I used back in May 2026, so I cannot simply rebuild and sign with the same credentials. Pls understand I am a 68 y.o Cancer patient with very low income and only can afford $10.00 Can someone be so kind and take that extra step and PLEAE assist me?

Here is where I stand:
• Mismatch type: SHA-1 key mismatch.
• I do not possess the original key at all.
• I’m unsure whether the best path is regenerating a new upload key, migrating to a new key signature, or starting a Play support request—so expert guidance is essential.

What I need from you
1. Diagnose the precise cause of the mismatch and confirm whether the current Play App Signing option allows an upload-key reset in my circumstance.
2. Lead me through (or carry out) the chosen remedy—be that generating a new upload key with keytool/Java Keystore, preparing the Google-issued “reset” request, or any other viable route.
3. Deliver a signed .aab or clear step-by-step instructions so I can submit the next build without further signature errors.

If tools like keytool, jarsigner, or Play Console’s “Reset upload key” flow are required, please be comfortable using them. I’ll provide the existing Play Console access and any files you need.

Success for me is simple: the new build passes the signature check and appears in the release dashboard ready for rollout.