Does your plugin support 3D Secure?

Yes, 3D Secure is implemented automatically if it is provided by the bank which has issued the debit/credit card.

The payment is successful in Phoca Cart, but it has pending status in Stripe dashboard

You missed Webhooks settings. Please, get Webhook URL and add it to Stripe settings.

How can I test payments

Enable Sandbox mode, add test API keys and use Test card numbers and tokens or Testing 3D Secure payments.

Stripe accept extra payments methods as iDEAL, Klarna, Sofortüberweisung, Apple Pay and other. How I can add them?

We provide two versions of Stripe plugin. Stripe plugin accepting payments via cards only. Stripe Checkout plugin accepting cards as well as allowing to include additional payment methods. You need Stripe Checkout plugin to enable and use additional methods!
The list of supported methods: (to be updated)
You can activate required payment methods from Stripe Dashboard. Go to Dashboard > Settings > Payment methods.
Enable additional payment methods in Stripe
Enable additional payment methods in Stripe.
Then enable and configure the required method(s). Do not forget to add the same methods in Phoca Cart Payment Method options.

I get error: 0 - Invalid API Key provided

This error means that one of the keys used in your plugin settings is invalid. Make sure that Publishable Key and Secret Key are valid.

There is no 3D Secure function to appear when a user makes payment.

3D Secure is a security layer supported by default, there is no longer a option allowing to enable/disable this important part of the payment making it secure (this option was in the earlier versions, but now it is obsolete). The appearance of 3D Secure depends on the bank-issuer of the card. If the bank supports 3D Secure layer, then the user will confirm the payment.