i use query monitor and i found out that b2b king gives me 6 errors

Non-static method B2bking_Admin::b2bking_register_post_type_customer_groups() should not be called statically Non-static method B2bking_Admin::b2bking_register_post_type_conversation() should not be called statically Non-static method B2bking_Admin::b2bking_register_post_type_offer() should not be called statically Non-static method B2bking_Admin::b2bking_register_post_type_dynamic_rules() should not be called statically Non-static method B2bking_Admin::b2bking_register_post_type_custom_role() should not be called statically Non-static method B2bking_Admin::b2bking_register_post_type_custom_field() should not be called statically