As-salāmu ʿalaykum Ustadh. If someone has a permanent medical condition and cannot fast voluntary Sunnah fasts at all, how can they still attain the reward of these Sunnah fasts? Is there an alternative way to earn the same reward? Apologies for asking again

Ustadh AbdulAziz al-Haqqan

If you used to do them and now you are not able to you get the reward because you are prevented, and if it is just your sincere intention that if you were healthy, you would do so, you get the reward of the niyyah, in sha'a Allah.