I assume you mean this:
Article 1 Section 4
The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing Senators.
But equally I see you do not understand it.
Nothing in 1-4 gives state legislatures any special powers. This is the merely and only the sharing of authority over federal elections with states. Nowhere in there does it say that state legislatures have any authority over elections different from their authority over laws in general. Now, the simple concept of our state governments is that they mirror the federal level: Legislature makes laws, Governor signs or vetoes laws, State Supreme Court interprets the laws. But it's not that simple. Governors also have the authority to put out Executive Orders, which is a way to alter laws.
So, think about election laws like any other law, because they are. Can Governors change aspects of laws through EO's? Yes. Can Supreme Courts reinterpret election laws or throw out parts they say are unconstitutional? Yes. Did those things happen before this election? They did. Did the governors and state supreme courts have the authority to do those things? They did.
One of the repeated lies on this board is the one that election laws are special, that legislatures write them and nobody else can say anything. Sunshine loves that lie, as does Curmudgeon. But that's what it is, a lie. Just look at Florida as an example. Florida Legislature had for decades refused to allow felons to ever get their voting rights back. Wouldn't even discuss it. So a Constitutional Amendment was passed in 2018 to allow felons to get their voting rights back after they served their time. Note that if only the Legislature was allowed to make election laws, this amendment would have never made the ballot, but evidently there can be provisions in the state constitution that override the Legislature. Then the Legislature passed a law that felons could only get their voting rights back if their paid their restitution first, which almost no felons are ever able to do, which basically invalidated the constitutional amendment. But then the Florida Supreme Court declared that law unconstitutional, and threw it out. Again, if only the legislature has authority over elections, then the state supreme court wouldn't have had that ability. But it seems they did. What does this mean? That the Article 1 Section 4 argument is flawed and invalid.
I've given up hope for Sunshine and Curmudgeon, but still hoping you have enough sense left to see a truth when it hits you in the face.