What is the reason for the slowness?

My site https://www.iskateknoloji.com/ is very slow, can you help me if I cannot solve it somehow?

iska wrote:

There could be multiple reasons,  It depends on server resources + hosting configuration + the code is not utilized for optimal performance, etc. (specifically I can see your home page takes a hell lot of time, but at the same time my account page loads faster.)

Who is your hosting service?
How much memory do you have?  (If you don't have enough, the app will constantly recycle.)

Check the System Log for any errors.  Check the log to see if you app is restarting often.
In Scheduled Tasks, use the "Keep alive" task.  The 300 second default is fine.

Thank you for your interest, I am sharing the screenshot of the diary.

https://resimlink.com/sxDg-zhl6

The log shows that your application is constantly restarting.   You probably need more memory.  The minimum you need is typically 1 GB of RAM, but 2 or 3 GB if you have a complex setup or many visitors.  Make sure you remove unused plugins.   After you uninstall them you also need to delete their subfolders in /Plugins folder.