Revised so that when the account selector finds the codes from the form, the journal entry editor is used to find the form instead of messing-up with the TransactionForm class and its static method that was a shortcut to the private instance method of the same name.

src/accounting/static/js/journal-entry-editor.js

@@ -150,6 +150,15 @@ class JournalEntryEditor {
         };
     }
 
+    /**
+     * Returns the transaction form.
+     *
+     * @return {TransactionForm} the transaction form
+     */
+    getTransactionForm() {
+        return this.#side.currency.form;
+    }
+
     /**
      * Saves the summary from the summary editor.
      *