For override {estatik-plugin}/templates/front/shortcodes/request/request-form-sidebar.php template move this file to {your-child-theme}/estatik4/front/shortcodes/request/request-form-sidebar.php where {your-child-theme}/ is name of your child theme.
For override all templates of [es_authentication] shortcode copy {estatik-plugin}/templates/front/shortcodes/authentication folder to {your-child-theme}/estatik4/front/shortcodes/authentication.
For override, all plugin templates in the child theme - copy all folders from templates directory to {your-child-theme}/estatik4/ folder.
So all templates of {estatik-plugin}/templates/ directory can be overridden in the child theme in {your-child-theme}/estatik4/ folder.
