أحسن الله إليكم Sheikh, do you only perform sujud as-sahu if you build your salah upon certainty and don't perform it when you build your salah upon what is most probable?

Imam Ibn ʿUthaymīn (may Allah have mercy on him) said: “If we adopt the stronger opinion, which is to follow what is most likely, then if it most likely seems to you that you did recite the tashahhud, there is no prostration upon you. But if it most likely seems to you that you did not recite the tashahhud, then you must perform the prostration.”