Thanks for conclusion.1.0 does not have a browser. However, if you want to get your OTP before updating, you will want to get yourself Cubic Ninja EU, download this and copy code.bin and load.bin to the root of the SD card (make sure the SD is formatted as FAT32 so the 3DS can actually read it!), scan the 1.0 QR code in-game. I believe the QR you want is the 2nd-lowest QR on this page: https://imgur.com/a/M67mE (If not, just try them all)
If you want to dump your NAND.img too (highly recommended), you should use this version of code.bin and load.bin (dump both NAND.img and OTP.bin).
Note that you will also want to dump your Xorpads, which (to my knowledge) does not have a publicly-known method to do so without updating your system. After you dump your OTP and NAND, use a cart to update to 4.x, use a DS-mode flashcart to install MSET ROP for RxTools and update the system to 9.2, then use Decrypt9 to dump your NANDFat16Xorpads and all the other Xorpads in the Decrypt9 menu.
Also note that you should not update to anything higher than 4.5, and that 4.1/4.2 are more likely to support more DS flashcarts than 4.3-4.5. Finally, keep in mind that a game card update will not give you the web browser, and this is your only (publicly-known) solution to get the xorpads from your 1.0 system.
EDIT: Special thanks to Normmatt for making the 1.0 QR dumping tools, and Plailect/d0k3 for the advice/support when I helped two other people dump with this method.
EDIT2: Actually nevermind about this being the only solution, you can dump your NAND.img with a hardmod (probably more dangerous if you don't know what you're doing), update to latest firm, downgrade NATIVE_FIRM via hardmod, downgrade to 9.2, dump xorpads, downgrade to 2.1, get the OTP, restore back to 9.2 and set up A9LH. Note that you'll still need Cubic Ninja to downgrade from 11.0.
According to Plailect's Guide, 2.0.0-2's browser seems to be unable to boot 2xrsa, which is different from 2.1.0-4 & 2.2.0-4's browser.
So is there any known 2.0.0-2's Cubic Ninja solutions?