Hi, @Expiscornovus
Thanks for the reply, you always post amazing solutions.
As I'm working with sharepoint list attachments, I don't use 'Get file properties'. I tried to adapt, but it is taking the property of the list item ID and not the attachment:

I used the same variables as you, inserting the data obtained in the developer toolbar on a network tab.
It's my first time working with json, maybe it's something obvious
When I try to use the code generated in developer toolbar, a bad gateway message appears, and a completely blank draft is created, with no file and no title:

{"LayoutWebpartsContent":"[{\"id\":\"@{variables('PageTitleWebPartId')}\",\"instanceId\":\"@{variables('PageTitleWebPartId')}\",\"title\":\"\",\"description\":\"\",\"serverProcessedContent\":{\"htmlStrings\":{},\"searchablePlainTexts\":{},\"imageSources\":{},\"links\":{}},\"dataVersion\":\"1.4\",\"properties\":{\"title\":\"@{outputs('Get_item')?['body/Title']}\",\"imageSourceType\":4,\"layoutType\":\"FullWidthImage\",\"textAlignment\":\"Left\",\"showTopicHeader\":false,\"showPublishDate\":false,\"topicHeader\":\"\",\"authors\":[],\"authorByline\":[\"@{outputs('Get_item')?['body/Author/Email']}\"]},\"reservedHeight\":228}]",
"CanvasContent1":"[{\"controlType\":3,\"id\":\"@{variables('CanvasContent1ControlId')}\",\"position\":{\"zoneIndex\":1,\"sectionIndex\":1,\"controlIndex\":1,\"layoutIndex\":1},\"webPartId\":\"@{variables('DocumentEmbedWebPartId')}\",\"webPartData\":{\"id\":\"@{variables('DocumentEmbedWebPartId')}\",\"instanceId\":\"@{variables('CanvasContent1ControlId')}\",\"title\":\"File viewer\",\"description\":\"\",\"serverProcessedContent\":{\"htmlStrings\":{},\"searchablePlainTexts\":{\"title\":\"@{outputs('Get_item')?['body/{Name}']}\"},\"imageSources\":{},\"links\":{\"serverRelativeUrl\":\"@{variables('varAbsoluteURI')}\",\"wopiurl\":\"@{variables('varAbsoluteURI')}\"}},\"dataVersion\":\"1.4\",\"properties\":{\"annotation\":\"\",\"authorName\":\"@{outputs('Get_item')?['body/Author/DisplayName']}\",\"chartitem\":\"\",\"endrange\":\"\",\"excelSettingsType\":\"\",\"file\":\"@{variables('varAbsoluteURI')}\",\"listId\":\"@{variables('varAbsoluteURI')}\",\"modifiedAt\":\"@{utcNow()}\",\"photoUrl\":\"@{replace(outputs('Get_item')?['body/Author/Picture'], concat(variables('SiteUrl'),'/_layouts/15/UserPhoto.aspx?Size=L'), '/_layouts/15/UserPhoto.aspx?Size=S')}\",\"rangeitem\":\"\",\"siteId\":\"@{variables('SiteId')}\",\"startPage\":1,\"startrange\":\"\",\"tableitem\":\"\",\"uniqueId\":\"@{variables('varETAG')}\",\"wdallowinteractivity\":true,\"wdhidegridlines\":true,\"wdhideheaders\":true,\"webId\":\"@{variables('WebId')}\",\"webAbsoluteUrl\":\"@{variables('SiteUrl')}\"}},\"emphasis\":{},\"reservedHeight\":686,\"reservedWidth\":1180,\"addedFromPersistedData\":true},{\"controlType\":0,\"pageSettingsSlice\":{\"isDefaultDescription\":true,\"isDefaultThumbnail\":true}}]","AuthorByline":["@{outputs('Get_item')?['body/Author/Email']}"],"TopicHeader":"","BannerImageUrl":"/_layouts/15/images/sitepagethumbnail.png","Title":"@{outputs('Get_item')?['body/Title']}"}