Can't resolve image into URL: undefined method `attachment_url' for #<#<Class:0x0 ...

Can't resolve image into URL: undefined method `attachment_url' for #<#Class:0x00007f9f6098f308:0x00007f9f6493d770>

I spent hours to solve it but nothing !!
Env: ruby : ruby 2.6.5p114 | Rails 6.0.2.2
what i did :
rails active_storage:install
rails db:migrate
has_one_attached :main_image
<%= f.label :main_image %>
<%= f.file_field :main_image %>
<%= image_tag event.main_image %>

Fixed 🎊🎉🥳
check : https://stackoverflow.com/questions/61715426/cant-resolve-image-into-url-undefined-method-attachment-url-for-class0x0