how to update or insert into lookup column using patch in power apps

Question

I have two sharepoint lists. Company, and Client Company= ID,Company,address Client: ID, clientname,email,clientID ClientID is a lookup number, and I allowed multiple selection in the lookup. Now on button click, I want to insert into Client sharepoint list using canva apps: here is my patch code onSelect button property:

Patch(Client, Defaults(Client), 
{
    clientname:clientnametxt.Text,
    email:emailtxt.Text,

//the problem stars from the lookup column. the value  is manually inserted in textbox and the id is exists in company
///i tried the following one by one, no luck!

//LookUp(Company,ID= Value(clientidtxt.Text))

                   
//Value(LookUp(Company, ID = Value(clientidtext.text) , ID))

//clientid:Value(clientidtxt.Text)

});

I have a wasted a week to figure out but still goes on, help me please

I have tried the code in comments but so far no solutions