How to delete my IPhone Safari history when I'm unable to click on the greyed out clear button?

I'm trying to delete the IPhone Safari History Bookmark but I'm unable to click on the Clear button--it is greyed out.

Under Settings, the option to "Clear History and Website Data" is also greyed out so that I can't click on it.

What can I do?

Do you have restrictions on? Go to Settings > General > Restrictions and make sure it's off. If it's on, you need the PIN number to turn it off. Once you turn it off, the clear option should be available.