Someone took a photo of the portion of the missile that hit the train station and it literally showed the serial number which traced back to AFU...so spare me the wikipedia bullshit.
“Russian media also said that the serial number of the missile was in the same range as one used by Ukrainian forces. Serial numbers cannot be used to prove which side fired the missile, however, since all Tochka-U’s were manufactured at a single site in Russia and distributed from there across the Soviet Union. As a result, there was, for example, a close serial number match between a Tochka-U used by Russia in Syria and one used by Ukraine in Snizhne.[40][41][42] Moreover, both Russia and Ukraine have made extensive use of munitions captured from the other side.[43][44]
A fake video clip with a mock BBC logo, attributing blame to the Ukrainian forces, circulated through pro-Russian telegram channels since 10 April. The video was also aired on Russian state television. The BBC has not produced any such video.”