Why doesn't Puerto Rico have anyone in Congress representing them?

As a territory (not a state) PR does not have Senators or House

Representatives. However, PR has a Resident Commissioner, a delegate, who is a member of the House of Representatives however without voting rights at the floor. The Resident Commissioner can be a member of House Commities, speak and vote on commities' public hearings / meetings, author / submit legislation, and participate in debates, just cant vote on legislation.

Current Resident Commisioner is Jennifer Gonzalez.

Only US states have Representatives and Senators in Congress. However, PR does have a Congressional delegation:

https://www.govtrack.us/congress/members/PR

It is NOT a state.

Because it's a US territory, not a state. Just like Guam and the US Virgin Islands.

PR has chose not to become an official state, if they did... they would have a congress rep and state senators. They also do not pay federal taxes and aren't subject to federal laws. Though they seem to want/get federal money still.

Because they chose NOT to become a State. This has been a political football for more than 50 years. They have a vote about statehood every couple of years and people get all worked up about it for a few minutes, but in the end, the majority of the people who live there DO NOT want Puerto Rico to become the 51st state. They prefer to remain a Commonwealth, so they don't have to pay taxes or abide by Federal laws.

Jenniffer González-Colón is the PR delegate to the House of Representatives. She does not have voting rights just like the Representatives from the other US Territories but that doesn't mean she is unable to get her voice heard.