Elementor is a WordPress third-party page builder, the Flexmls IDX WordPress plugin has been compatible with Elementor since version 3.10.
In your default WordPress page editor click on the Edit with Elementor button…
In the left column scroll down through the list and find the Flexmls option:
Drag and drop a flexmls widget to the Add Element box. The widget settings will appear in the left column:
Please see our Widgets page for more information on each widget option