There are many ways to make it.

Some of them are

23*1=91 -- **2+3*1=5**

---> 1 move to make 9 as 5.

2 moves to make 1 as + sign.

23*1=91 -- **3*3*1=9**

---> 1 move to make 2 as 3.

2 moves to make 1 as * sign.

23*1=91 -- **23/1≠91**

---> 1 move to make not equal.

23*1=91 -- **23*1<91**

--- 2 moves to make greater sign from equal sign.