How do you fire one particle per iteration? What is the function?

Hello, I am a newbie but I want to make an addon in which the object will fly out one particle on a keyframe, driver, etc. within the particle system that-that this one particle works according to the set parameters of the particle system. Let’s say the particle is a projectile from the muzzle of a weapon and this particle will fly out after its call (not to be a chaotic rain as in conventional particle systems).

Question, how to use the code to call only one particle?

And, additionally, optional. Does anyone know the principle of implementation so that particles can be given a rate of fire per minute?

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