Hydro turf recommend weldwood red label, I struggled to find that in the UK and used a branded contact adhesive/cement (one you apply to both surfaces let tack off then put together)
Word of advice - be careful make sure everything is aligned if you don't and the adhesive grabs you might need a new section
When I did mine I taped them all in position aligned properly and put the rear section on first but I masked around the edges of the mat so I knew how far to go with the adhesive without making a visible mess, just mask and repeat with every section n job done!