I think what you want is Admin UI Extensions, here the docs
→ Overview: https://shopify.dev/docs/api/admin-extensions/2024-01#overview
→ Extension target (order list page included here): https://shopify.dev/docs/api/admin-extensions/2024-01/api/extension-targets#extensiontargets-propertydetail-adminorderindexactionrender
→ Here the Shopify tutorial: https://shopify.dev/docs/apps/build/admin/actions-blocks/build-admin-action?extension=react
Hope you deploy your app/extension soon! 