The Torah is written in Hebrew - and like basically ALL ancient Hebrew (and most modern Hebrew also) it is written without any vowels.
As you can see, Sefaria declines to translate it at all, but simply transliterates the traditional vocalization of the words, and, in fact, this version is vowelized text (the traditionally understood text as spoken has had the vowel markings ADDED - in the form of dots and dashes above and below the actual letters:
וַיֹּ֤אמֶר אֱלֹהִים֙ אֶל־מֹשֶׁ֔ה אֶֽהְיֶ֖ה אֲשֶׁ֣ר אֶֽהְיֶ֑ה וַיֹּ֗אמֶר כֹּ֤ה תֹאמַר֙ לִבְנֵ֣י יִשְׂרָאֵ֔ל אֶֽהְיֶ֖ה שְׁלָחַ֥נִי אֲלֵיכֶֽם׃
And God said to Moses, “Ehyeh-Asher-Ehyeh,” continuing, “Thus shall you say to the Israelites, ‘Ehyeh sent me to you.’”
The LETTERS for 'ehyeh' are Alef, Hey, yod, hey. in MODERN Hebrew, that would be 'I WILL BE'
But Biblical Hebrew handles verb tenses differently - it is one of the relatively few differences between modern and Biblical Hebrew, actually (that and some vocabulary).
Besides, the vowel sounds ATTACHED have a lot to do with the meaning of the ROOT - And the traditional vocalization MIGHT not be right, and there is no way to know, because ALL of the possibilities make perfect sense.
Without the vowels belonging to those consonants, it is literally IMPOSSIBLE to know exactly what this version of 'be' actually says - so
At any rate, the HYH root does mean 'to be/is'.
- I am what I am is right
I will be what I will be is right (and maybe is exactly right)
I am what I will be/was/am - is right.
All of them are right.
Sadly, this always makes me think of Popeye.
I yam what I yam.
And - unfortunately - that is pretty much exactly what it means. It means what it needs to mean.
I am, however, perfectly content with the meaning of 'asher'. It means what, or which.