Spark claim help

Hi, I am trying to insert my metamask address into the message key on the xrp toolkit. All is going well and when I update the metamask account details in the Message key this message appears" unable to sign, none of your added accounts can sign this transaction".
Any info would be appreciated.

A MetaMask community user may be able to provide assistance, but I encourage you to contact Spark support as well. They should be able to assist you, since the error was received on their platform.

Spark/Flare has been unresponsive to my requests for help. I created a support ticket about a week ago and no response. Very disheartening.