السلام عليكم ورحمة الله وبركاته احسن الله إليك If someone has an issue of urinary incontinence and the Adhan for the next salah starts. If they already have impurity in their garments and don’t have a clean replacement, what should they do in this situation?

In these situations, you should be careful and bring something with you because you already suffer from this problem. If you find yourself in a situation where you don't have a clean change, then you can go home quickly and bring some change. If you are not able in any way, shape, or form, then what you do is you wash it so that you can pray. You wash the impure spots, and then you can pray, inshaAllah.