submission error message

So my wordpress site domain is from Godaddy, and hosted in a hong kong server, as our target users are mainly from hong kong. When i wish to improve SEO and started submitting backlink to directory sites, i always get the error message of "The URL could not be validated. Either the page does not exist or the server cound not be contacted."

I have read from another platform that someone commented: You're getting the error because you're using an SSL that belongs to someone else. When these directories attempt to verify your site using the "https", they get a warning that says your site is potentially harmful and the third party SSL is the reason given. My suggestion would be to buy an SSL directly from your web host or from a reputable SSL company."

But unfortunately, i can't ensure if this is the right direction and how can i do that.
Could someone teach me please? By the way my website link is , hopefully you can find some clues with the link. Thanks in advance.
https://www.bananaportal.com/

 

I have no clue how to help you, but FYI I get the following message when I go to your site:

 

damn, but i can browse it properly, i'm in London UK right now... May i know where do you browse from?? Ugh i feel so pissed rn. Also, would you be able to tell what caused that?

 

Hi, do you get that error at all of the directory sites you attempt to place your link on? eta: And have you tried submitting without the httpS?