Troubleshoot & Resolve Issues with Website Coding for SSL Cert

The previous web company responsible for my website has gone out of business, and I have been handed over to another agency. However, this new agency is unable to understand the coding language used in my website and is unable to resolve the issues I am facing. Currently, my website is live but hidden behind a warning page due to an expired SSL certificate. I am hesitant about their suggestion to re-create the website since it is serving as a temporary holding site until the larger project is built. I am looking for a skilled coder who can understand the coding language used in my website and provide clarity on the difficulties we are facing in accessing the backend and resolving the SSL certificate issue. The goals are to regain access to the backend and resolve the SSL certificate problem without necessarily recreating the entire website.

Requirements:
- Proficient in the coding language used in the website (will need to be established by a knowledgeable person)
- Experience in troubleshooting and resolving issues related to SSL certificates
- Ability to understand and work with an existing website structure
- Good communication skills to provide clarity on the difficulties faced and suggest alternative solutions if necessary

Deliverables:
- Identify and troubleshoot the issues preventing access to the backend of the website
- Resolve the expired SSL certificate problem and ensure the website is secure
- Provide clear explanations for the difficulties faced in accessing the backend
- Suggest alternative solutions if these difficulties cannot be overcome on this forum

My website is: www.loveoutdoors.co.uk