I want to change the button text "儲存 & 關閉" to be "儲存(僅一品項)".
But I do not want to use the thanslation of language.
I had wroten the javascript code to change the button text successfully in the google chrome devtools' console.
I do not know wehere should I put the javascript code.
Should I put the javascript to start function or another place?
Should I transfer the javascript to the javascript of the odoo syntax?

Those are the javascript as below:

var elements1 = document.getElementsByClassName('btn btn-sm oe_button btn-primary o_formdialog_save');
if (elements1.length == 1)
{
	var e1 = elements1[0];
	e1.textContent="儲存(僅一品項)";
}