How to reorder columns in bootstrap4 in mobile version?

Question

Bootstrap

<div class="row">
        <div class="col-md-3">
         sidebar1
        </div>
        <div class="col-md-6 mb-4 pr-md-0 pl-md-0 ">
          {content}
        </div>
        <div class="col-md-3">
        siderbar2
        </div>
      </div>

The question is very simple, but for the life of me I can not understand what the catch is.
The trick is that the grid already exists (above) and cannot be changed. It is necessary that in the mobile version the central block with {content} be at the very top and in turn below the sidebar.
Tried through all sorts of offsets but I can't figure out how they work

Answer 1

<div class="row">
        <div class="col-md-3 order-1 order-md-0">
         sidebar1
        </div>
        <div class="col-md-6 mb-4 pr-md-0 pl-md-0 order-0 order-md-1">
          {content}
        </div>
        <div class="col-md-3 order-2">
        siderbar2
        </div>
      </div>