invoking example snaps

[leopashov]

I'm developing a snap locally and wanted to invoke the 'get-entropy-example-snap' at https://metamask.github.io/snaps/test-snaps/latest/, but I get this error:
'{
"code": -32603,
"message": "http://localhost:8000 does not have permission to invoke npm:@metamask/get-entropy-example-snap snap.",
"data": {
"originalError": {}
}
}'.
Is this because the example snap does not have:
"endowment:rpc": {
"snaps": true
},
set within it? If so, are there any snaps which do have the endowment which I could test with?
Failing this, is there a way of getting around this that's easier than building it locally and pointing to that?
Many thanks!