Unable to change the Rate inquiry result screen

Hello Team, 

I am trying to modify the rate inquiry screen (result page).

For this I am trying to add an external link with manager layout but this gives error related to access .

Though the user is given the Admin in Access control list but still not able to access the same.

Attaching the Screenshot of the system with detail about the manager layout & URL.

The business wants to reorder the columns in the results screen in the Rate Inquiry but somehow not able to achieve it

I am on 20C version .

Thanks

Mrugen