Hi guys, I am glad to inform you that HTTPS is now official for blogger users. Google started by releasing HTTPS for sub-domains and now users of custom domain can also enjoy this offer. To enable this is pretty simply.

Before now, Blogger custom domain can only enable HTTPS from draft.blogger.com. This can be done by going to draft.blogger.com and then to Settings > Basic Settings and then turning it on. With the Google make the SSL official, users can now enable HTTPS with out going through this long process. All you need to do is head up to Settings > Basic Settings, under Basic settings, locate HTTPS and turn it on.

Source: http://www.techchairman.com/2018/04/https-now-available-for-custom-blogger.html