Questions about XFX Radeon RX 6600 Speedster

Hello good morning everyone Markus here. This is my system, AMD RYZEN 5 3600, 32 GB RAM, Asus Rog Strix B 450 f2, now have a GTX 1660 SUPER OC 6gb, with 3 fans, power supply Seasinic 550 Watt 80+gold zertific. The Asus mainboard has only 3.0 PCI e, looking for a Grafikk, up to 400,.Euro, does anyone have an idea. Many thanks in advance Greetings Markus.