Query all homepage blocks from GraphQL

Hey guys,

Thank you for your amazing module.
I have just a question about it. Since few days, i make query to understand all possibilities of queries but I don't understand one thing.

I know that you can query all blocks in region for a node (ex Article type or other) but I'm trying to query all blocks for the HomePage.
I tried to make a query like this :
`{
route(path: "") {
...on EntityCanonicalUrl {
blocksByRegion(region: "content") {
entityLabel
}
}
}
}`

but it doesn't work... Can someone explain to me how I can make this ? Or if I must maybe make my own resolver ? Is it possible with 3.0 version ? :)

Thanks again and have a good week,