“只有得到它允许的东西才可以进出”如何翻译这句话？

如果"进出"的对像就是上文的"它"(比如一间密室),则可以翻译成:
Only things permitted by it have the access to it.
如果"进出"的对像不是上文的"它"(比如,一只狗守着一间房子,"它"指的是狗,"进出"的对像是房子),则可以翻译成:
Only things permitted by it can get in and out.