The Messenger of Allah ﷺ said, "Whoever lies about me, let him take his seat in the Fire, let him take his seat in the Fire." He said it twice like this.He repeated it to us another time and said, the Messenger of Allah ﷺ said, "Whoever lies about me deliberately, let him take his seat in the Fire."
حدثنا إسماعيل أخبرنا سليمان التيمي قال سمعت
قال رسول الله ﷺ من كذب علي فليتبوأ مقعده من النار فليتبوأ مقعده من النار هكذا مرتين وثنا به مرة أخرى فقال قال رسول الله ﷺ من كذب علي متعمدا فليتبوأ مقعده من النار
Its isnad is sahih. It has already appeared at 12700.12736m - Abdullah told us, my father told us, like this twice, and he told it to us another time, and said, the Messenger of Allah ﷺ said, "Whoever lies about me deliberately, let him take his seat in the Fire." Sahih.(12736m) Its isnad is sahih.