Hey @alinadumitru2312,
For the separator, this is added by the Stripe plugin when the Payment Request button feature for ApplePay and GooglePay buttons has been activated within the Stripe plugin settings.
Below is the settings from WooCommerce > Settings > Payment > Stripe which enables the seperator element.

Image Link: https://cloudup.com/cKonE2OF6ne
Inspecting your site the ApplePay button is displaying but something on your site is affecting the display of the button causing it to look like a vertical line instead of a button.

Image Link: https://cloudup.com/cDBaLFUiFKV
It seems like either the WordPress theme you’re using or the Elementor Page Builder plugin you’re using is breaking the CSS output for the ApplePay payment request buttons preventing those from displaying properly.
What you’re experiencing is not however directly related to the Stripe plugin itself from testing on my own installations. On all of my test installations, the ApplePay payment request buttons are displaying correctly like this example below.

Image Link: https://cloudup.com/cb75qvoZgUc
We’d suggest carrying out a conflict test on your site by disabling all other plugins aside from WooCommerce and Stripe along with switching to a theme like Storefront. This will help with trying to and locate what software you have installed which could possibly be causing this behaviour? You could use a free plugin called Health Check and Troubleshooting to carry out such testing.
When in Troubleshooting mode all plugins will be deactivated and only the admin of the site carrying out the troubleshooting would see those changes. Any customers visiting the site would see no changes at all.
Once you have disabled all other plugins and switched themes if the behaviour is resolved you can then enabled your theme and sites plugins testing after each one is enabled until the behaviour returns to locate the culprit.
https://docs.woocommerce.com/document/how-to-test-for-conflicts/
I hope this helps.