You need to actively show people your inner self too! My aggressive behavior is part of that!
Literal
Inner-self [object-を] understanding receiving [for-ための] appeal [also-も] necessary [copula-なのさ]! My aggressive action [also-も] that inside [possessive-の] one!
内面 ('inner self, inner nature') and アピール ('appeal, self-promotion') mix Japanese and loan vocabulary. ~てもらうための ('for the purpose of having someone understand') is a complex purpose construction. のさ is the masculine explanatory ending with さ (filler/assertion). アグレッシブ ('aggressive') is the loan. ボク is the soft masculine first-person. The character is defending their extroverted behavior as strategic self-presentation.