Provided the certificate is installed properly, the padlock is to appear in the address bar and can be seen by anyone who visits your site on any browser that they may use.
Note: From September 2023, the new version of the Chrome browser will replace the padlock symbol with a tune icon. This update is occurring as the secure HTTPS connection is now standard practice online, according to Google, and it is no longer required as a trust indicator. This means the tune symbol will not serve as a trust indicator, but it will provide a clear, clickable way for users to get more information about the site they’re visiting, such as its connectivity settings. Moving forward, the absence of security warnings will define the safety of a website’s connection.