soql malformed in REST API on where clause for useremail

while running this code in anonymous window getting the error below

        String useremailaddress="test@test.com";
        HttpRequest req = new HttpRequest();
        String query='SELECT+id+,+uuid__c+from+User+WHERE+Username="+useremailaddress;
        req.setEndpoint("callout:salesforceauthnam/services/data/v56.0/query?q='+query);
        req.setMethod('GET');
        Http http = new Http();
        HTTPResponse resp = http.send(req);
        system.debug('Body:'+resp.getBody());

Getting error malformed on where clause

[{“message”:”\nuuid__c from User where Username=”test@test.com“\n ^\nERROR at Row:1:Column:53\nBind variables only allowed in Apex code”,”errorCode”:”MALFORMED_QUERY”}