Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency help if your child:
Contact a healthcare professional the same day if the soft spot is bulging while your baby is calm and upright, especially with fever, repeated vomiting, poor feeding, or unusual sleepiness.
A bulging soft spot is different from a hard suture ridge and may indicate pressure or illness that needs prompt assessment.
Arrange a routine appointment if the ridge remains after early newborn molding has settled, becomes more obvious, or is accompanied by an unusual head shape.
Also book an appointment if you are concerned that the head is not growing, the face or eyes look uneven, or your child has developmental difficulties.
The article also says
A stable ridge without these symptoms is not usually an emergency.
However, persistent ridging with an unusual head shape should not be left until much later, because early assessment can clarify whether normal growth is occurring.
Every sign above is quoted from the sofidex article on Sutures - ridged. If you are not sure, err upward — it is always reasonable to be checked.