Put (one) on (one's) mettle verb phrase
To put one in a situation in which they must show their worth, skill, or ability.
I know the manager's unexpected question is to put me on my mettle.
The first round is used to put candiates on their mettle.
If you have somthing good like your appearance, skill, or talent, you should show them off.
To prove one’s worth or skill
To show that you are good at doing something.
If you make something stick, you prove that it is true.
The verb "put" must be conjugated according to its tense.
Mettle was originally only a variant spelling of metal that became increasingly linked with metaphorical meanings of the word, meaning "quality of temperament," and from there "natural spirit" or "courage."These senses ultimately diverged so much from the literal meanings that it was no longer obvious that they were the same word. To differentiate the two, the separate spellings metal and mettle were in use by the early 18th century, albeit not widely until the next century.