The option for creating a site template isn't available for me.
So what I did is go to SharePoint Designer and in the "Site" tab under "Site Options", I set "SaveSiteAsTemplateEnabled" to "true". Then I navigated to "/_layouts/15/savetmpl.aspx" directly to save my template and then downloaded it from the SiteCollectionGallery.
Now I want to create a site using this template but my template isn't appearing int the template list.
Note : When I go to Site Settings -> Site Administration -> Click Create in the Sites and Workspaces dialog, I see for a brief moment other templates before being redirected to the page without my template. I copied the link before being redirected and got this message :
An error occurred while processing your request.
Thank you for your help.