Hello and welcome to the forum 
Krita doesn’t have that particular filter/function but there are ways to do it.
There is this topic:
That gives two possibilities:
Selecting the lineart then growing/shrinking the selection and painting over it.
Or adding a Layer Style of Stroke then adjusting the thickness of the stroke.
If the linart is black on white with no acute corners, you can blur it then use Filter → Adjust → Threshold to increase or decrease the thickness.
That gives pixellated edges so a 1px blur afterwards may give an improved appearance.