Kalamint uses Temple Wallet browser extension for transactions.
You will be able to download the extension from https://templewallet.com/
Once downloaded, please ensure your wallet shows Tezos Mainnet as shown below next to the profile image:
To fund your wallet, click on the wallet address to copy it as shown below:
Once the address is copied, you can go to any exchange that has XTZ listed and send the desired amount of XTZ to the Temple Wallet address (copied in the previous step), which would be your withdrawal/receiving address.
If you are using Binance, you will have to select Tezos in the options provided under Transfer Network as shown below:
Wait for a few minutes for the transaction to be confirmed on the blockchain and you will have the funds in your Temple Wallet.
You can use the Connect button on the Kalamint site to connect your wallet and start transacting.