How to fill a DateTime column in indexed db using JsStore

Here is my table :

{
        name : "TEST",
        columns : {
            K_A : {dataType : "string"},
            DT_VAL : {dataType : "date_time"},
            DT_SENT : {dataType : "date_time"},
            pk: {
                primaryKey: true,
                keyPath: ['K_A', 'DT_TRACE']
            },
            sent: {
                keyPath : ["DT_SENT"]
            }
            
        }
    }

I’m totally unable to insert a record in this table. I’ve no idea of the format for a Datetime column. I tried almost all solutions :new Date(); Date.now(), new Date().toISOString(), new Date().toGMTString(), new Date().toUTCString(), new Date().toString()…. nothing works.

dt=new Date().toISOString();
record={ K_A:"A", 
         DT_VAL: dt,
        DT_SENT: dt 
        };

// Using jsStore
db.connection.insert({
into: “TEST”,
upsert:true
values : record,
validation: false});

Whatever I try, I get this :

 Uncaught (in promise) 
Object { message: "Data provided to an operation does not meet requirements.", type: "DataError" }