I lived and worked in a foreign country for all of 2019 and 2020 but have a PA driver's license. Do I need to pay state income tax still?

Most likely- the Pennsylvania Department of Revenue states:

"A person’s domicile does not change until he or she moves to another state or country with the sincere intention of making his or her permanent home there and abandoning his or her previous domicile. If a person moves to another state or foreign country but intends to stay there only for a fixed or limited time (no matter how long), his or her domicile does not change."

If you intend to change your domicile permanently and have taken steps to establish a new domicile where you are living now, you probably abandoned your Pennsylvania domicile (in which case you should cancel the driver's licenses as well).

In order to establish a new domicile, the following three conditions must be met:

• There must be evidence of a firm and definite present intention to discontinue making the former domicile your primary base of operations;
• There must be evidence of a firm and definite present intention to make the new domicile your primary base of operations; and
• There must be evidence of actual physical presence and actual abode (transient, temporary, or permanent) in the new location.