Can the certificate of resignation be used as the work certificate of immigrants?

It's better not to do this. The certificate of resignation is very unfavorable to your immigration, so it is better to issue a formal employment certificate. It doesn't matter if you change jobs. Don't use the certificate of separation. The separation certificate will make the immigration officer think that you are not good enough, so you will be dismissed by the company. You can only disclose resignation information after you get your identity or visa, or you can't disclose it at all. The thinking of foreigners is different from that of China people. We can't think about immigration according to China people's thinking, which is very risky.

Four years' work proves that it doesn't matter to go abroad separately. You still need to ask a professional for guidance, otherwise you will be killed and you don't know why you refused to sign. Which country are you going to?