200cc is the same as 200ml. Years ago I bought some and the mix was 180ml to 16 litres water. but I never used it so cant say if its the right mix.
For ivy I used to cut off right at the base/ bases, remove as much as possible and then weed killer on what is left. Then spray every week until dead, (thats the ivy is dead, not you.)

What is the name of the weed killer that was recommende to you and which co-op do you advise,please

Damm (down by the river in Amposta) has Glyphosate or Glyfosato in Spanish (that's the generic name and there are lots of brands) at 18E/5 litres at the moment which is the cheapest I've seen it in five years,  It's the same as Roundup but a lot cheaper. 200ml/cc per 16 litres is about right but if you haven't done it before I'd suggest it's heavy to lug around.  I find that 10L at a time is manageable so use 120ml/cc in 10 litres of water and add a small dash of washing up liquid (helps to wet the leaves).