Finding positions of minimum values in list

Question

I would like to find the positions of multiple occurrences of a minimum value in a list. For instance, for the list {1, 2, 1, 3}, I want to obtain the two positions for the occurrences of the number 1.

MinimalBy[{1, 2, 1, 3}, id (x)] gives me these occurrences, but not the positions.

Answer 1

lst = {1, 2, 1, 3};
Random`Private`PositionsOf[lst, Min @ lst]

{1, 3}

Also

 Flatten@Position[lst, Min @ lst]

{1, 3}

Answer 2

list = {1, 2, 1, 3}
PositionIndex[list][Min[list]]

{1, 3}

Answer 3

o.k. as suggested by Syed, here comes my answer: As of Mathematica Version 13.2:

list={1,2,1,3}
PositionSmallest[list]

{1, 3}

Also there is:

PositionLargest[list]

{4}