How to exclude in content articles (<img class= and )

Hi, i need to configure the Echo RSS, for this feed : https://frontonline.net/rubrika/lajme/feed/?post_type=book With the <b>Strip HTML Elements by Class: attachment-full </b> and <b>Strip HTML From Content: Selected</b> I have full text in on paragraph, only text without photo and div. and without selected <b>Strip HTML From Content</b> I have in content post Do you help me please to resolve this error/problem? Best regards