After securing your website Here is how to change HTTP to HTTPS in Google search console or webmaster tools. Both version of your HTTP (not secure) and HTTPS (secure) needs to register or added to a single account
Google search console considers both the version as two different properties or websites. It will do 301 redirects and verification for both sites

FIRST, Go/login to your account, open/select the HTTP or not secure of your site and choose the settings option

SECOND, Click on change of address option under settings

THIRD, Expand the domain or URL rectangular, choose the HTTPS or secure version and click on the validate & update button

LASTLY, A popup page for validation will be shown and click on the confirm move button
