Hello. Who can advise? Such a situation, in the organization there is …

Hello. Who can advise? Such a situation, in the organization there is such a system of vacations, if a person first started working (or left maternity leave) in August, then vacation (every year) can take only from July of the current year. Question, if a person leaves maternity leave from April 10th, 2022, can he take the vacation in full or only part, for the worked months? And how will the vacation pay be calculated?