Must I strive to earn money to pay the expiation for an oath, which is feeding ten poor people, or is it permissible for me to fast due to not currently having the money, knowing that I am able to earn but am not working?

If you are unable to expiate an oath by feeding or clothing, then expiate by fasting. You are not required to seek out money for that, as inability arises from the absence or non-existence of funds. Some scholars have mentioned that whoever has absent money and cannot find anyone to lend to them, should expiate by fasting. The criterion for inability, which permits one to fast, is that one does not have in excess of the sustenance for himself and his dependents for the day and night the amount needed for expiation.