Hello Richard,

There are a few ways to approach that:

• There is a thread in our Feedback Portal (link here) for a feature request that might suit your needs. If public methods for controlling the grid are implemented you will be able to invoke them from buttons anywhere on the page. I have given your Vote for it. You could also Follow it in order to receive email notifications for future status updates.
• Another way of doing it is to use a custom form for editing or adding (for examples click here and here).
• A third way could be by relocating the GridCommandButton "Add" by surrounding it in a div and use the position CSS property to put it anywhere on the page where you require. Here is a short sample:
  

  <GridToolBar>
          <div style="position:*position options*>
              <GridCommandButton Command="Add" Icon="add">Add Item</GridCommandButton>
          </div>
  </GridToolBar>

If neither of these work for you or require any further assistance, please do not hesitate to contact us. 

Regards,
Svetoslav Dimitrov
Progress Telerik

 UI for Blazor