Warning: Cannot modify header information

Hello, I installed Satispay plugin to handle those payments, but when I try to save settings I get this error:

Warning: Cannot modify header information – headers already sent by (output started at /home/customer/www/atmosphere.it/public_html/wp-content/plugins/woo-satispay/wc-satispay.php:188) in /home/customer/www/atmosphere.it/public_html/wp-admin/includes/misc.php on line 1431

I already tried to reinstall the plugin but no change. Can anyone please help? Thank you in advance.

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