Translation:I get the check this time.
It should be understood by all native English speakers. I'm Australian and we say "bill" here but I'd be surprised if any Australians didn't understand stuff like "check please".
Of course without enough context and depending on the phrasing it could be misunderstand due to "check" also being a verb.
"I get the check" is NOT correct English, and no native speaker would ever say that. The phrase is "I'll get the check." Even a 'aloppy' native speaker would never say "I get" in this context. It's simply unnatural, and hope you'll correct it, esp. if the system is suggesting to foreign learners that that's an acceptable phrasing.
That's probably acceptable as an idiomatic translation into American English. Elsewhere in the course they have a totally different Chinese sentence equated with "It's my treat". I think it's "wo qing ni" so since there's not a literal way to translate that into Chinese the idiomatic translations should work there and here.
"I get the check" is just bad English. It should be "I'll get the check"
"Will" doesn't always mean future in English, in fact this is why English doesn't really have a future tense. It also indicates will or volition. But also in English we can use "will" for the present and the future and not using can also be used for the present or future. But it depends on other things. In this case "I get the check this time" sounds like foreigner English but "I'm getting the check this time" and "I'll get the check this time" both sound perfectly fine
I don't mind getting an answer wrong but, as a suggestion for the designers, adding the 'will' would repair this nicely. In addition, I'd suggest taking the 'want' out as a block choice because communicatively you could argue that this sentence relays a desire to pay for the check. I didn't choose "I get the check" because it doesn't signal willingness so I used "I want the check" even though though there was no Xiao or yao in the sentence.