Astrophoto Stacking

Hello All,
I was lucky enough to capture few pictures of the Comet C/2022 E3. But the real trouble came when i started to process those pictures and stack them. I used the tool Siril and with the help of few youtube videos i tried to stack them. But the result was not as good as expected.
I have around 30 pictures (Exp 20 sec, F5.6 and ISO 800) Can anyone guide me on how to stack those photos?