Good evening.
There are two options:
1) You can buy an ssl certificate (as an example here
https://ssl.com.ua/ or wherever it is more convenient for you) for a year or 2 years.
The resulting certificate files must be installed on the server.
2) you can install a free certificate from Let's Encrypt. This certificate is valid for 3 months. But there is a possibility of an extension.
If you do not have access to your server, we can provide you with access.
If we install, it is 1 hour.