Add allowed content type in document set

Question

I'm developing a feature with 2 content types; A document set and a picture

I need that my document set allow my second content type Picture.

I've tested this but nothing happens if Igo to manage document set

    <?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <!-- Parent ContentType: Document Set (0x0120D520) -->
  <ContentType ID="0x0120D520003E4980F3009045648C71163A63AFE9C1" Name="DocumentSetGeolocation" Group="test" Description="My Content Type" Inherits="TRUE" Version="0">
    <FieldRefs>
      <FieldRef ID="{99afd525-b766-4249-b933-de94c987d218}" DisplayName="N° chantier" Required="FALSE" Name="N_chantier" />
    </FieldRefs>
    <XmlDocuments>
      <XmlDocument NamespaceURI="http://schemas.microsoft.com/office/documentsets/allowedcontenttypes">
        <act:AllowedContentTypes xmlns:act="http://schemas.microsoft.com/office/documentsets/allowedcontenttypes" LastModified="1/1/2010 08:00:00 AM">
          <AllowedContentType id="0x010102003139F2673D35495C861AF26048B55D78" />
        </act:AllowedContentTypes>
      </XmlDocument>
      <XmlDocument NamespaceURI="http://schemas.microsoft.com/office/documentsets/defaultdocuments">
        <dd:DefaultDocuments xmlns:dd="http://schemas.microsoft.com/office/documentsets/defaultdocuments" AddSetName="TRUE" LastModified="1/1/2010 08:00:00 AM">
          <DefaultDocument name="PictureGeolocation.xsn" idContentType="0x010102003139F2673D35495C861AF26048B55D78" />
        </dd:DefaultDocuments>
      </XmlDocument>
    </XmlDocuments>
  </ContentType>
</Elements>

Answer 1

Write-Host -f Green "Adding Content Type to Document set: DocumentsetName"
Add-SPOContentTypeToDocumentSet -DocumentSet "DocumentsetName" -ContentType "picture"

Use SharePoint Online PnP https://github.com/OfficeDev/PnP