Wondering if you can provide info on how to create a valid certificate stored only on my device to access via HTTPS, without getting downgraded to HTTP, or showing up as no certificate in my browser?

Using Brave Beta as a browswer, but would imagine this issue would be valid for any browser, as no certificate is generated for accessing the router via local management, even when I check "Local Management via HTTPS."

Any help is appreciated.

Thank you