JPA Sort order by according to primary key entity field

Question

My application uses Sort.Order ASC and DESC.Is there a way for unsort, if sort has not been passed the repository search results should always be passed based on entity primary key asc sort?Similar like how to achieve oracle order by 1 in JPA

if (inputSort != null) {
            Sort sort;
            if(inputSort.getDirection().isAscending()){
                Sort.Order order = new Sort.Order(Sort.Direction.ASC, inputSort.getSortByField());
                sort = Sort.by(order);
            } else {
                Sort.Order order = new Sort.Order(Sort.Direction.DESC,inputSort.getSortByField());
                sort = Sort.by(order);
            }
            
            pr = PageRequest.of(page, size, sort);
} else { 
            pr = PageRequest.of(page, size);
}