Apt key expired

[Firesphere]

When updating with apt, I get the following error:

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://apt.hyperion-project.org bullseye InRelease: The following signatures were invalid: EXPKEYSIG 0E6710C4A760E210 Hyperion Project <admin@hyperion-project.org>
W: Failed to fetch https://apt.hyperion-project.org/dists/bullseye/InRelease  The following signatures were invalid: EXPKEYSIG 0E6710C4A760E210 Hyperion Project <admin@hyperion-project.org>
W: Some index files failed to download. They have been ignored, or old ones used instead.

[Paulchen-Panther]

hyperion-project/hyperion.ng#1607 (comment)