HTTPS for WWW and without WWW for my site

Hi,

I run a website getdohelp.com. What I am facing problem is as below.

In the boot site hosted on Godaddy with SSL and everything was going well. The site opened well with www or without www, but after a while we have a speed problem and 503; so we are changing server and are currently using VPS or Bigrock.

Our SSL was on Godaddy and when we install it on our site, it is redirected automatically to https://getdohelp.com. Previously, our site index with www and we also submitted the sitemap to Google with www so we would get a software error notice.

Is there a problem with the SSL installation? … I'm not sure and that's why ask. I'm using SSL for the first time on one of our sites. Means suggest.

I've tried to manage it from htaccess, but it's a redirection error that does not redirect properly.

What I want is that our website should open with www or without www normally. Please suggest to me that how can I do it. I want to solve this problem as soon as possible.
SEMrush

Website developed in PHP cake.

I hope your suggestion will be faster and better.