Open Terminal and Send the corresponding command and wait for it reaches the target temperature.
PLA: M109 S190
Or you can change filament with Touchscreen by going to 3D printing > change filament.
❗Please be careful and DO NOT touch the hotend.
💡Tips: Press the ring with thumb and index finger and drag the tube with other fingers.
Keep inserting the filament until you see some filament coming out of the nozzle and couldn't insert deeper.