Firstly your must change your body position. Different positions can relieve some of the pressure on your bladder and make it easy to hold in urine. 
if you have a gas then pass it. It may help to hold urine.
To hold urine if you stay warm then it will help you.
Avoid thinking of water, waterfalls, or rain.
Minimize drinking anything while you need to pee. 
Don't laugh loudly or think about anything funny.
Don’t go for a swim and don't think about water.
https://www.wikihow.com/Hold-in-Pee-when-You-Can%27t-Use-the-Bathroom