I was finally able to solve this, took a bit but here it is:
USING lvgl v9.3
in the screens.c file I had to add
objects.lblbut_scan = obj;
lv_obj_set_pos(obj, -1, 0);
lv_obj_set_name(obj, “scan_button_label”); << added to set the name
in my main.ccp code had to get reference to the object
Getting the button required
lv_obj_t * objbutton = lv_obj_get_child_by_name(lv_screen_active(), "scan_button");
lv_obj_t * objbuttontxt = lv_obj_get_child_by_name(objbutton, "scan_button_label");
by doing that I was able to
lv_label_set_text(objbuttontxt, “scanning…”);
more code was required but there are 2 steps needed