As explained in the article dedicated to the use of ash in the vegetable garden, I can confirm that ash is a useful organic fertilizer, even if it is not a complete fertilizer, as it is especially rich in potassium, while it is poor in nitrogen. It is also a substance rich in limestone, therefore strongly basic, not to be used on acidophilic plants like most berries.
Wood or pellets
The fact that the ash is obtained by burning wood logs or pellets does not change the final result: the pellets are nothing more than pressed wood waste, they are obtained from shavings and sawdust. Obviously not all pellets are the same and the type of ash varies depending on what has been burned. If good quality pellets are burned in the stove, for example those obtained from virgin beech wood, the ash will be equivalent to that created by burning a beech log and can be used in the garden.
As I mentioned, the ash must be used with awareness to enrich the soil of the vegetable garden, accompanied by other nitrogen fertilizer and without exaggerating, I refer to the article on ash for some more information.
I hope I was useful, a greeting and good crops!