Can I use this plugin for custom location? For example, I insert short code in header or menu like below image, and this plugin show other languages to the users.
The plugin only implements hreflang using link elements added to the page header. At the moment, it does not include a built-in language or country selector feature. If you’d like to add a country selector, this would currently require either an additional dedicated country/selector plugin or a custom implementation.
From your screenshot, it appears that your site is using a separate plugin called Hreflang Flags. This plugin supports shortcodes, and you can find its documentation in the /doc/ folder included with Hreflang Flags.
Please note that we’re only able to provide support for Hreflang Manager in this forum. For any issues related to other plugins, such as Hreflang Flags, we recommend reaching out with the methods described on our support page.