Pencil torch not holding it's flame

I have a BerzOmatic butane pencil torch. It is not holding it’s
flame, gutters out after lit for maybe a minute. It’s most of the way
full.I have not used this torch much, I do not understand why it’s
giving me trouble after minimal usage.

Btw, I am doing small work. A small penc il torch is all I can afford
right now.

Liz