NSA 6700 Howto LACP ?

Dear Community,
I am very confused about the documentation. I have a NSA 6700 here and would like to create an LACP channel via 2 10Gbit interfaces.
Which ports can I use for this?
It says here:
https://www.sonicwall.com/support/technical-documentation/docs/sonicos-7-1-system/Content/Interfaces/interfaces-link-aggregation-limitations.htm
“LACP only works with interfaces connected to the internal SonicWall switch.” -> What does that mean?
When I go to Network -> Switching -> Link Aggregation in the Web Gui and then to “Add LAG Port”, I only have X0, X1, X15 and UO to choose from. :-(
I also tried it on "NETWORK" → "Interfaces" but this Link Aggregation does not appear to be LACP.
Please help.
Best,
David
Answers
I haven't done this myself yet on a SonicWall, but from what I understand you need a configured "parent" interface which SonicOS calls "aggregator port". First configure one of the interfaces the way you want and use that as the aggregator port, then add member ports for it.
I'm not entirely sure what internal SonicWall switch means, I was wondering that myself recently. According to this article Gen 6 hardware had limitations on what ports could be used for link aggregation:
https://www.sonicwall.com/support/knowledge-base/how-to-configure-link-aggregation/170505763142649
If doesn't reference Gen 7 having any limitations so I'm hoping those limitations have been removed. At least when playing around on the demo site all the ports are selectable for link aggregation, but that's read-only so can't be sure if any limitations come up during saving changes.
I did some try and error:
1.) "NETWORK" → "Interfaces" → Link Aggregation is static, no LACP
2.) Network -> Switching -> Link Aggregation is the right way. The interface appears after putting it into a zone and give it an IP address (makes no sense in my eyes but than it appears in the drop down list).
@Sonicwall We need a better documenation!