Should i raise the lamp to force the strech?

Encouraging stretch isn't something I'd typically recommend for an indoor grow. First off, your plant is gonna stretch plenty in flower most likely, some plants can double or even triple in size. Second, space is an important commodity indoors and stretch is just bare stem, aka wasted space probably. Lastly, your grow light has powerful light but the further away stuff is from it the weaker the light- so by encouraging the plant to get tall you ensure less of your plant is in the optimal zone of light.