On-chain transactions require network confirmation to complete the crypto transfer - there has to be an agreed number of confirmations by miners. Technically speaking, 1 confirmation is considered to be confirmed. More confirmations ensure your transaction won't be amended / rolled back in the forked chain.
The time it takes for an on-chain transaction to complete depends on the network traffic. If you want your transactions to be completed faster, you can choose to pay a higher network fee.
For tokens like XRP/XLM, the network fee is fixed and confirmation time is consistent so there will not be an option to select the confirmation speed.