You need a 14MM Allen key or similar sump plug key.
The size wrench to remove it should be 15mm.
A washing machine should typically have a drain size of 2 inches to effectively remove water and prevent clogs.
13mm
Use a proper size box-end wrench or socket to remove the oil drain plug
It seems to me I use a 15 mm wrench to remove the engine oil drain plug.
14mm
15mm.
15mm
11/16th
T40
14mm
15 mm