By the Elementor

First, be sure your site has installed the Elementor - Header, Footer & Blocks plugin (From Appearance Install Plugins)
Elementor - Header, Footer & Blocks
Step 1 - Go to Appearance → Elementor - Header, Footer & Blocks to add new footer
Step 2 - Edit your footer with the Elementor plugin then Publish
Step 3 - Final go to to Appearance Theme Options Header and Footer to select your footer (Select Elementor Builder Mode)