Samsung Galaxy Tab A7 (SM-T500) - Stuck on boot screen?

I'm new to this, and I think I've got a problem. I hope someone can help me. I tried to flash a Samsung Galaxy Tab A7 (SM-T500), but encountered the following issue: I followed the instructions and thought I did everything correctly. However, when the tablet boots up now, I see this screen: > Reason recovery: Public key used to sign data does not match key in chain partition descriptor. > > dtbo: Error verifing vbneta image https://postimg.cc/gxXfqzDt " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> I restarted it and it won't boot to the Samsung OS anymore. I started comparing the screens to ones I saw in a YouTube video. I noticed that there should be three entries in the boot menu on this screen (https://postimg.cc/R6gRDYQp) , but I only have two. The missing entry is for vbmeta. Is there anything I can still do?