I think I might just get mine at Walmart's bicycle department. You may want to look beyond Walmart. The last time I looked 12 speeds (cogs) were widely available. Yours appears to be a 9 speed.
9 posted on 01/05/2021 9:54:35 AM PST by DUMBGRUNT
("The enemy has overrun us. We are blowing up everything. Vive la France!"Dien Bien Phu last message.)