Automatic re-sorting is not possible with Numbers. However, you can avoid choosing your preferred order every time by creating a sorting rule and then using the Sort Now menu option in iPadOS Numbers as follows:
To create a sorting rule:
- Select a table to sort, or select just specific rows in a column to sort.
- Tap the Organize button, tap the Sort tab, then tap Entire Table or Selected Rows.
- Tap Add a Column, then tap a column to sort by.
- By default, the column sorts in ascending order. To change this, tap the rule in green below the column name.
- Tap Done.
To apply a sorting rule:
- Activate the table to be sorted by tapping anywhere on that table.
- Tap the Organize button, tap the Sort tab, and then tap Sort Now.
- Tap Done to go back to the table which should have been been sorted now as specified in the rule.
For more, see the "Sort table data in Numbers on iPad" Apple support webpage.