Call an electrician?

Yes first will try to splice myself, that’s the second option. Checking if there’s a easy way or method

If that is the main power line into the house I do not think I would want to splice it, even for temporary power.

Clamps like this and several layers of electrical tape.

https://www.menards.com/main/electrical/electrical-tools-accessories/terminals-connectors/inline-wire-connectors/gardner-bender-reg-8-awg-copper-split-bolt-connector-2-count/gsbc-8n/p-1444431006801-c-6445.htm?tid=7084041211845044936&ipos=3

I wouldnt splice a main wire ever.

Hi, You may want to use a "split bolt"> Looks like a horse shoe with a nut on the end. i used them on to wire up large electric motors on cranes. Never had one fail. They come in different sizes so take a piece of wire with you.

Good Luck Woodbutcher

Several years ago while replacing a fence post cut one of the mains. Electrician (licensed) repaired with a splice and a sealing heat shrink tubing. Never had any more problems. This was a buried line.

Thanks folks… got one of those split bolts from Home Depot and all good now !