How to edit (Update, Delete) app owned metafields??

[Shahaab_Manzar]

I have successfully created a app owned Metafield and am able to access it in the liquid file.
currently the value of  {{ app.metafields.call_to_action_dummy.background_color }} is "#fff123" I want to change it to "#fff" how should I go about it?

I have gone through this: https://shopify.dev/docs/apps/custom-data/metafields/manage-metafields#step-3-update-a-metafield. (Updating metafield for Product but how to do it for app owned metafields).

Please give me example for it. Thanks