Is it permissible for my husband to perform tayammum, and how does he perform it, and does he perform it for every prayer, given that he cannot perform wudu' due to an injury on his face?

If a man fears an increase in illness or a delay in recovery due to washing his face, he should perform a complete ablution (Wudu') except for the face. Then, he should perform Tayammum (dry ablution) after the Wudu' to compensate for the missing part. With this, he can pray only one obligatory prayer. If he performs Tayammum due to an ailment, he may pray one obligatory prayer and as many supererogatory prayers as he wishes with it. If he desires to pray another obligatory prayer, he must repeat the Tayammum.