That’s Android 9.
It is, but Google Play Store won’t offer it to your device because your OS doesn’t meet the minimum requirements. Current versions of the Wyze app require Android 10:
Thank you for including information about your firmware and app versions! 
That helps to explain your situation:
Those are incompatible:
In addition to trying a smaller card (32 GB or smaller), please do make sure that it’s formatted FAT32. Some users have reported that having other things on the card often causes problems, so you may have your best chances of success by using a freshly-formatted card and ensuring that the only thing you copy to the card’s root directory is the single .bin file that’s necessary to flash the firmware. You must download the .zip file from Wyze’s repository, decompress it, and extract this .bin file from the archive. The recovery_wcv4.bin file should be the only thing you put on the microSD card before inserting it into your Cam v4.
I wonder if you’re trying to rename the .zip file because of Step 4 in the instructions. Although Wyze recently edited the instruction to clear up some confusion, that particular Help Center article still has problems, and the instruction about renaming the extracted file seems unnecessary and potentially confusing.
Another thing that can be helpful is using a power strip. Holding in the SETUP button while plugging in the Cam can be tricky for some people. When I have to flash a Cam, I plug it into a switched-off power strip, insert the microSD card into the Cam, hold in the Cam’s SETUP button, and then flip the switch on the power strip while continuing to press the Cam’s SETUP button for 3-6 seconds or until the status LED turns purple.
Please note that flashing back to older firmware should be considered only a temporizing measure. You’re likely to have better results with your Wyze products and your mobile experience overall if you can make plans to replace your phone with something running a currently supported operating system, particularly since Android 9’s last security update was released over four years ago.
Please also understand that I don’t fault anyone for using older technology, especially if part of the goal is to reduce e-waste and keep things out of landfills, and I noted my own uses of older tech in a topic I linked above. I just think it’s important to understand the risks involved (e.g., missing important security patches) versus the benefits of using something more current.