For the Newsletter Manager Free plugin, only one widget is available.
In the premium plugin, XYZ WP Newsletter, we can use multiple widgets.
Also we can add the short code in other sections or pages.
The short code is [xyz_em_subscription_html_code] for the free plugin Newsletter Manager which is available in XYZ Newsletter > Opt-in Form.
In the XYZ WP Newsletter premium plugin you can create multiple subscription forms and their corresponding shortcodes are available. The shortcodes are present in XYZ WP Newsletter > Opt-in Form.
Note: You cannot use the same Newsletter Manager/XYZ WP Newsletter shortcode multiple times in a single page.