Please help with Stock/Custom Rom for Bluboo s8a

I was trying to root bluboo s8a with TWRP following this tutorial When I reached step 2 of installing the ROM with sp flash tools, the ROM installed up to the end but the phone stopped powering (doesn't show anything). I tried downloading other customs ROMs for bluboo s8 but they were customized to be flashed with TWRP because they had no scatter files. I landed on one custom ROM which I flashed into the phone with sp flash tools and the phone powered on and I could hear the sound when I press the buttons and when the phone is powering on but the screen shows a dark screen. I would like to go back to the stock ROM or a working custom ROM. I took some screenshots of the settings of the About Phone before trying the rooting process. " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> About Phone (click images for larger variants) **Update:** Now I have gotten some ROM from the seller's website. It's in a zip file with one .cpb file and a folder named dbs. The folder has two files. When I try flashing the .cpb file with QGDP, I get an error of CPB Package is not complete. How can I overcome this please?