The claim that the Trump family plans to leave America if Trump loses the election is false. The claim is in a post on X (formerly known as Twitter) by an account called 'PoliticsVideoChannel'. This tweet has no information besides the title itself and an unrelated picture of the Trump family.
Upon further research, I found that the closest thing to a source that this tweet could be based on is an interview that Elon Musk and Trump had. The direct quote stating that "If something happens with this election, which would be a horror show, we’ll meet the next time in Venezuela, because it’ll be a far safer place to meet than our country. So you and I will go and we’ll have a meeting and dinner in Venezuela.” (Vanity Fair).
However, the implication that the entire Trump family would move to Venezuela if Trump lost cannot be sufficiently claimed from this source (which wasn't given in the tweet). Overall this claim is false and misleading and has no linkage to any credible sources.