Cruel Labryinthe. Forgot to spend ascendancy point before hitting portal

can i spend some how still?

You have to be in Lab to do the ascendancy points. You should be able to run the easy lab if you wish to. Check /passives, it should say you have 2 available unallocated points, in which case you should be able to run any lab you can enter/complete to alter them. There is not a way to alter them without being in the reward room as far as I know.

You could also do it when you get your next lab, if it is not too difficult levelling without them. Although someone a few days again said they were blocked from entering 3rd lab. I think they had not completed second lab at all though.

You don't need to spend the points in the lab aside from the exception of changing ascendency. However, you do need to hit the altar in the back before hitting the portal to get credited for that lab completion. If you haven't used the altar next to the portal for that level you'll have to redo it.