Its continuation of problem started in
"I've checked your site and found that you have enabled SCA option in Stripe payment app. In case of SCA enable Free trial not supported. In Non-sca , free trial can be used."
"The reason why trials do not work with SCA is because Stripe does not allow the amount of 0 for SCA. A minimum of 1 is required for payments."
I contacted Stripe support and its looks that its not like that
Recurring payments with free trials are supported by Stripe but you have to manage its according to their dev doc.
See answer from stripe
" From: Stripe <email@example.com>
Sent: Tuesday, May 19, 2020 4:00 PM
To: GrzegorzSzyszka <firstname.lastname@example.org>
Subject: Re: Stripe sales inquiry
I appreciate you raising these concerns.
Setting up a subscription with a free trial is actually possible if you are using Stripe Billing as shown in the document you’ve shared.
The idea here is to create the subscription today specifying a specific number of trial_period_days or trial_end date. "
See Stripe doc.
Looknig forward to your answer