They’ve depicted it twice in the series Vikings. The first time was the most explicit when Ragnar executed Jarl Borg. The second time was when Ivar the Boneless killed King Aella in revenge for killing his father.
That first time - for Jarl Borg - I thought that it was chosen as a way to honor the guy? I must be thinking of some other death sentence, where the guy was honorable, but he had to be punished and executed. But executed in such a way that he still made it to Valhalla. (Or perhaps I’m confabulating three different story-lines!)
I do recall a battle where some old guy joined them in hopes that he would be killed in battle so would go to Valhalla.