Makes use of user-inputted text to access metafields

metafield-key.liquid

<!-- Metafield list -->
{%- liquid 
  assign image_key = section.settings.image | downcase | replace: " ","_"
  assign image = article.metafields.my_fields[image_key].value
  
  assign title_key = section.settings.title | downcase | replace: " ","_"
  assign title = article.metafields.my_fields[title_key]

  assign text_key = section.settings.text | downcase | replace: " ","_"
  assign text = article.metafields.my_fields[text_key]

  assign caption_key = section.settings.caption | downcase | replace: " ","_"
  assign caption = article.metafields.my_fields[caption_key]
-%}

<!-- e.g. section.settings.image is of type 'Text' in the schema -->