How does Austrian Economics deal with monopolies?

Not trolling…. genuinely trying to understand this.

I think the idea of “natural monopolies” not occurring seems incorrect. How can we look at what’s happening today and not conclude there are certain companies that have narrow competition to an insignificant % of the free market? So maybe not technically a monopoly but the supply chain is artificially constrained (think Walmart’s effect on many industries). How would Austrian Economics propose to solve the current situation?