how to pass json object in URL via a GET parameter ?

Hello,

I have the following code that works fine :

= Json.Document(Web.Contents("https://myurl/documents", [Headers=[Authorization="Bearer "&GetToken(),#"profile"="full-access", #"enduser"="enduser"]]))

But when I add the parameter "search" that takes some json like this :

= Json.Document(Web.Contents("https://myutl/documents?search={"_type":{"$eq":"Document"}}", [Headers=[Authorization="Bearer "&GetToken(),#"profile"="full-access", #"enduser"="enduser"]]))

It works fine with Postman but Power Query tells me there is a syntax error under "_type".

I have the same issue when I add this :

= Json.Document(Web.Contents("https://myurl/documents?search={
                              "$and": [  
                                        {"_type": {"$eq":"TOTO"}},
                                        {"$or": [
                                                 {"g_service":{"$eq":"FR_Moto"}},
                                                 {"g_service":{"$eq":"FR_Moto2"}},
                                                 {"g_service":{"$eq":"FR_Moto3"}}
                                             ]}
                                     ] 
                              }", [Headers=[Authorization="Bearer "&GetToken(),#"profile"="full-access", #"enduser"="enduser"]]))

The syntax error is under the first dollar sign before the and

Is the issue that we must concatenate strings in json differently in PowerQuery ?