An upload banner has been created at https://github.com/Wikidocumentaries/wikidocumentaries-ui/blob/master/src/components/topic_page/Banner.vue

The banner is placed under the header on each page that has P1435 declared. The banner has an upload button that takes to the upload campaign.

The list of required properties is manually maintained in Banner.vue

Issues
The WLM campaigns have been designed to work with manually maintained lists in Wikipedia with a variety of ids which is sent to the campaign in the id parameter. Finding the right id in Wikidata is a complex task. However, it would be possible to send only the Wikidata id to the campaign to cut corners. This would require changing all campaigns to accept a wikidata id value as structured data or otherwise. The value should be added on top of the current values not to break existing templating etc.

The banner is tested with items in India and in Finland before it can be used more broadly.

The banner texts are localized in https://translatewiki.net/wiki/Translating:Wikidocumentaries.

Examples
https://wikidocumentaries-demo.wmflabs.org/Q679764?language=en
https://wikidocumentaries-demo.wmflabs.org/Q4950212?language=bn