Extend the aluminum posts of the patio roof

Good day I bought a terrace roof made of aluminum today which is still assembled at the seller. Since we have to mount the wall rail higher for fastening, the two front posts are now too short. Now I need advice What options are there to extend them? I have attached a photo. We need an extension of about 30-40 cm per post (2 pieces) At the moment the posts in the front are 2.05 meters, which is too short. I would be grateful for tips to find a solution. [ATTACH alt="AF545AAD-A8D0-4ED8-9E9A-2BB6590179E9.png"]90917[/ATTACH] Buying new posts would be the very last option. An extension would not disturb visually, as there are flower boxes in front.

A base under the post solves your problem

If it is to turn out well, it involves some effort. Buying the two posts new is probably almost cheaper.
Get aluminum profiles of the same thickness, have them cleanly welded and ground down. It is best to insert a square metal tube beforehand for reinforcement/stiffening. Then have the entire post powder coated anew.
Find someone who has welded aluminum before.

If it is to be good, it involves some effort.

It doesn’t have to - he wrote that there are flower boxes standing in front. So it primarily has to be cheap, in which case just put a base underneath each one and that’s it. Possibly even directly in a flower box - acquaintances have done that (similar issue), looks quite decent.

Thank you for the answers
Since we have dismantled our previous metal pavilion
(was also expensive, but no
wall mounting), the massive posts are now left.
These are also 1 cm narrower in width than the newly acquired ones.
So now we will slide the old ones into the newly acquired ones and virtually screw them together crosswise at the overlap with threaded rods at the right height.
The weight does not rest only on 2 front posts, but additionally, with the wall mounting, it also rests on a rear one with the [Fette].

Since our house wall is insulated (10 cm plus plaster), we now need to buy the right screws and anchors for the wall mounting.

I am grateful for any tips.