Does Linode require owning a mobile device?

You should be able to use any app that supports TOTP, regardless of device. We recommend Authy in our guide, which is supported on desktops:

• https://www.linode.com/docs/guides/linode-manager-security-controls/#select-a-token-application
• https://authy.com/

With that said, the purpose of 2FA is to increase the difficulty for an attacker to compromise your account. If you use the same device for 2FA as you use for entering your password, the value of the additional layer of security is somewhat diminished.

Bitwarden (a password manager) also has 2 factor authentication with a premium subscription.

There’s also Yubico keys. Some of their keys also have 2 factor authentication built in.