You mean it pronounce 1st as "one" "s" "t" instead of "first"?

The brute force solution is to defined it under dictionary.voice
[words]
1st="first"
2nd="second"
:
!_a**="Australia"
:

But it is cumbersome especially if you have like hundreds of them. So we need to find a way to defined it via pattern.

Under config_numbers.lua there is definition for
ordinals = {
{L"first", nil, nil},
{L"second", nil, nil},
{L"third", nil, nil},
{L"fourth", nil, nil},
{L"fifth", nil, nil},
{L"sixth", nil, nil},
{L"seventh", nil, nil},
{L"eighth", nil, nil},
{L"ninth", nil, nil},
{L"tenth", nil, nil},
{L"eleventh", nil, nil},
{L"twelfth", nil, nil},
{L"thirteenth", nil, nil},
{L"fourteenth", nil, nil},
{L"fifteenth", nil, nil},
{L"sixteenth", nil, nil},
{L"seventeenth", nil, nil},
{L"eighteenth", nil, nil},
{L"nineteenth", nil, nil},
{L"twentieth", nil, nil},
}

If somehow we can use that definition and pattern like (for all the 'th)
;numberTH spacer
/(?i)([\s,\.]r_art_s.*[\s,\.][1-9]+)([tT][hH][\s,\.].*r_art_e[\s,\.])/-->"\1th"