Err:6 https://repo.skype.com/deb stable InRelease
The following signatures were invalid: EXPKEYSIG 1F3045A5DF7587C3 Skype Linux Client Repository <se-um@microsoft.com>
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://repo.skype.com/deb stable InRelease: The following signatures were invalid: EXPKEYSIG 1F3045A5DF7587C3 Skype Linux Client Repository <se-um@microsoft.com>
W: Failed to fetch https://repo.skype.com/deb/dists/stable/InRelease The following signatures were invalid: EXPKEYSIG 1F3045A5DF7587C3 Skype Linux Client Repository <se-um@microsoft.com>
W: Some index files failed to download. They have been ignored, or old ones used instead.
This is coming when I am going to update my Ubuntu via terminal. Could you please suggest to me how can I update my Ubuntu?
Thanks in advance.