No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
I know what it is. But it doesn't apply here.
But this is a civil trial not a criminal trial. If you take the 5th Amendment in a CIVIL trial, that can be held against you.
https://www.law.com/thelegalintelligencer/2022/09/15/pleading-the-fifth-and-civil-litigation-is-it-a-good-idea/
Secondly, Trump is not taking the 5th here. The state has rested their case, this is Trump's defense. So he is declining to testify in his defense.
He was called as a witness by the state and he testified then. He did not take the 5th, because as I said the judge could hold it against him.