Hi @Anonymous ,
Could you please share a bit more about your scenario?
Do you want to format the entered value 12345678900 as 123.456.789-00?
I assume that you would enter 11 digit value within the Text Box, according to the needs that you mentioned, I think the OnChange property of the Text Input Box could achieve your needs.
I have made a test on my side, please try the following workaround:
Set the OnChange property of the Text Input Box to following:
If(
Len(TextInput1.Text) >= 11,
Set(
FormattedValue,
Left(
Left(TextInput1.Text, Len(TextInput1.Text)-2),
3
) & "." &
Right(
Left(
Left(TextInput1.Text, Len(TextInput1.Text)-2),
6
),
3
) & "." &
Right(
Left(TextInput1.Text, Len(TextInput1.Text)-2),
3
) & "-" & Right(TextInput1.Text, 2)
)
)
Set the Default property of the Text Input Box to following:
FormattedValue
Please check the following GIF screenshot for more details:

Note: The OnChange property of the Text Input Box would be fired only when the focus is moved away from the Text Input Box
If you want the entered value within the Text Input box to be formatted automatically, I think the Timer control could achieve your needs. You could consider add a Timer control in your app, set the Duration property to following:
1000
set the AutoStart and Repeat property of the Timer control to following:
true
set the OnTimerEnd property to following:
If(
Len(TextInput1.Text) >= 11,
Set(
FormattedValue,
Left(
Left(TextInput1.Text, Len(TextInput1.Text)-2),
3
) & "." &
Right(
Left(
Left(TextInput1.Text, Len(TextInput1.Text)-2),
6
),
3
) & "." &
Right(
Left(TextInput1.Text, Len(TextInput1.Text)-2),
3
) & "-" & Right(TextInput1.Text, 2)
)
)
Set the Default property of the Text Input Box to following:
FormattedValue
Please consider take a try with above solution, then check if the issue is solved.
Best regards,