Are the prayers that were performed in Ramadan from the 1st to the 20th, with a small amount of urine coming out after using the lavatory and during ablution, valid and sufficient, or must they be repeated, and if repetition is necessary, how should the make-up be performed?

The questioner is not considered to have urinary incontinence. Rather, the discharge of a drop of urine necessitates performing ablution again. He is not required to make up the prayers during which he doubted whether urine had been discharged, as the default assumption is that it was not. As for the prayers during which he was certain that urine had been discharged and he did not perform ablution, he must repeat them because they were invalid. In summary, he is not required to make up any prayer unless he is certain that he prayed it while in a state of ritual impurity.