Casement window in need of weather seal strip

I recently became a homeowner and within the first month and during the first rainy day my kitchen casement window started to leak water. I'm very positive that it's due to the weather strip seal. The only part number is the one attached in the pictures, also in the hardware there is a name ROTO by north America I called them but they only carried hardware not weather seals. Hopefully you guys can help me.