{%- paginate section.block by 5 -%} is not working. why?

{%- paginate section.block by 5 -%}

{%- for block in section.blocks -%} {%- assign collection = collections[block.settings.collection] -%} {%- assign alignment = block.settings.alignment -%}

{%- assign onboard = false -%}

{%- if collection == blank -%}
{%- assign onboard = true -%}
{%- endif -%}

{%- if onboard == false and collection.image -%} {% include 'rimg', img: collection.image, size: '350x', lazy: true %} {%- elsif onboard == false and collection.products.first.featured_media.preview_image -%} {%- assign product = collection.products.first -%} {% include 'rimg', img: product.featured_media.preview_image, size: '350x', lazy: true %} {%- else -%} {%- capture index -%} {%- cycle '1', '2', '3', '4', '5', '6' -%} {%- endcapture -%} {{ 'collection-' | append: index | placeholder_svg_tag }} {%- endif -%}
{%- unless onboard -%} {{ collection.title }} {%- else -%} {{ 'collection.item.onboarding.title' | t }} {%- endunless -%} {%- if display_description -%} {%- if onboard -%}

{{ 'collection.item.onboarding.description' | t }}

{%- elsif collection.description != blank -%}
{{ collection.description }}
{%- endif -%} {%- endif -%}

{%- endfor -%}

{%- endpaginate -%}

Section blocks cannot be paginated.