Oops, you're on Android. This is for desktop. Please ignore.

There are two different menu options for Firefox.

orange Firefox button
Next to History is a triangle which leads to a menu to "Clear Recent History"

classic Menu Bar
On the Tools menu is "Clear Recent History"

To customize your History settings, you can use this dialog:

orange Firefox button or classic Tools menu > Options > Privacy tab

If you change from "Remember history" to "Use custom settings for history" you get a wide range of options.

Any luck?

In Settings, look for Clear Private Data.