Safari does not show "Clear History" - Catalina, iMac late 2015

Thanks for your help, but sorry, it didn't work that way - I checked with "D" and there is no hardware problem also. In some comments I saw that there might be set some restrictions. But I couldn't find that button also. Cookies can't be deleted also.

i did and for the it is readable but grey - sorry

Sorry for the typo: I restarted and now "Clear History..." is visible. But it does not work because it appears as inactive (grayed out).