My hosting provider says, “We have already provided CSR for domain 360fashion.net and anina.net. Please provide the above CSR to the SSL provider and ask them to reissue the SSL certificate. Please get back to us with the SSL certificate so that we can install the SSL for the domain.”
I ran this command: site5.com who is my provider, have asked to have you issue the SSL certificate so that they can install it. I have the CSR that they provided (a long bunch of numbers and code looking stuff) but i have no idea where to submit that to you to get the SSL certificate that they require so they can then install it.
It produced this output: I"m not sure how to get the SSL certificate to you or where to submit the CSR that they have provided
My web server is (include version): no idea
The operating system my web server runs on is (include version): no idea
The model Let's Encrypt encourages is, when using shared or managed hosting, for your hosting provider to implement automated ACME software so that the only work you have to do -- if any -- is press a single button and your hosting company's software will automatically issue a certificate and then renew it in the future.
Many hosting companies support this.
Requiring you to manually obtain certificates is more complicated and error-prone for you, and means your website will break if you don't go through the same process to renew it every 2-3 months.
If you use a common control panel, like cPanel, it should have easy-to-use integrated certificate support (with Let's Encrypt or an alternative CA).
Vote with your wallet and use a less user-hostile host. I'm not being snarky here; your host has made a user-hostile business decision and should feel the pain. There are hundreds of web hosts who support Let's Encrypt out of the box, and you have a link to the list above.
The cert will be valid for 90 days, so you should renew it before then.