Cant access add plugin in wordpress

Hi guys,

I need some help from professionals here from wordpress.
I am using a wordpress site and suddenly i have this issue of not being able to install any plugins.
I could still view them but i cant add any new plugin and i get this error

An unexpected error occurred. Something may be wrong with www.remarpro.com or this server’s configuration. If you continue to have problems, please try the support forums.

and then i checked with a health app to see whats wrong with my site and i found this.

Error Your site is unable to reach www.remarpro.com at 198.143.164.251, and returned the error: cURL error 7: Failed to connect to api.www.remarpro.com port 443: Connection refused

I have a feeling this both are connected and i could use some help from someone professional here. I have access to the Cpanel and i could use some hand here.