In WP Admin go to Templates → Saved Templates → Import Templates and upload the downloaded .json file.
Open the target page with Elementor, click the folder icon → My Templates, and insert the imported template.
Images referenced by Figma render URLs are sideloaded into the Media Library during import — those URLs expire after ~30 days, so import promptly.
Set fonts and top colors as Global Fonts / Global Colors in Site Settings so the theme stays consistent as you refine.