When "appreciate" means "to thank or be grateful for something", it must be followed by "it" or "impersonal nouns" but not "personal nouns or pronouns" with an "if-clause".
E.g. We apologize for any inconvenience caused and would appreciate
it if you could treat this matter as urgent.
And you can not say " I would appreciate
him/her if he/she could help.

Again, Not a teacher.